diff --git a/bazel/carbon_rules/defs.bzl b/bazel/carbon_rules/defs.bzl
index ef52903bb076..b1a4f8b36dd2 100644
--- a/bazel/carbon_rules/defs.bzl
+++ b/bazel/carbon_rules/defs.bzl
@@ -4,6 +4,7 @@
 
 """Provides rules for building Carbon files using the toolchain."""
 
+load("@bazel_tools//tools/cpp:toolchain_utils.bzl", "find_cpp_toolchain")
 load("@rules_cc//cc:action_names.bzl", "ACTION_NAMES")
 load("@rules_cc//cc/common:cc_common.bzl", "cc_common")
 load("@rules_cc//cc/common:cc_info.bzl", "CcInfo")
@@ -26,8 +27,10 @@ def _carbon_binary_impl(ctx):
     # Pass any C++ flags from our dependencies onto Carbon.
     dep_flags = []
     dep_hdrs = []
+    dep_api_files = []
     dep_link_inputs = []
-    for dep in ctx.attr.deps:
+    deps = ctx.attr.deps + ctx.attr._default_deps
+    for dep in deps:
         if CcInfo in dep:
             cc_info = dep[CcInfo]
 
@@ -46,16 +49,16 @@ def _carbon_binary_impl(ctx):
                     dep_link_inputs += lib.objects
         if DefaultInfo in dep:
             dep_link_inputs += dep[DefaultInfo].files.to_list()
+        if CarbonLibraryInfo in dep:
+            carbon_info = dep[CarbonLibraryInfo]
+            dep_link_inputs += carbon_info.objs.to_list()
+            dep_api_files.append(carbon_info.api)
 
     # Add the dependencies' link flags and inputs to the link flags.
     link_flags += [dep.path for dep in dep_link_inputs]
 
     # Build object files for the prelude and for the binary itself.
-    # TODO: Eventually the prelude should be build as a separate `carbon_library`.
-    srcs_and_flags = [
-        (ctx.files.prelude_srcs, ["--no-prelude-import"]),
-        (ctx.files.srcs, dep_flags),
-    ]
+    srcs_and_flags = [(ctx.files.srcs, dep_flags)]
 
     objs = []
     for (srcs, extra_flags) in srcs_and_flags:
@@ -76,13 +79,14 @@ def _carbon_binary_impl(ctx):
                 src.short_path.removeprefix(ctx.label.package).removesuffix(src.extension),
             ))
             objs.append(out)
-            srcs_reordered = [s for s in srcs if s != src] + [src]
+            srcs_reordered = dep_api_files + [s for s in srcs if s != src] + [src]
             ctx.actions.run(
                 outputs = [out],
                 inputs = depset(direct = srcs_reordered, transitive = dep_hdrs),
                 executable = toolchain_driver,
                 tools = depset(toolchain_data),
                 arguments = ["compile", "--output=" + out.path, "--output-last-input-only"] +
+                            ["--no-include-carbon-core"] +
                             [s.path for s in srcs_reordered] + extra_flags + ctx.attr.flags,
                 mnemonic = "CarbonCompile",
                 progress_message = "Compiling " + src.short_path,
@@ -119,19 +123,164 @@ def _carbon_binary_impl(ctx):
 
     ctx.actions.run(
         outputs = [bin],
-        inputs = objs + dep_link_inputs,
+        inputs = depset(direct = objs + dep_link_inputs),
         executable = toolchain_driver,
-        tools = depset(toolchain_data + prebuilt_runtimes),
+        tools = depset(direct = toolchain_data + prebuilt_runtimes),
         arguments = full_link_flags,
         mnemonic = "CarbonLink",
         progress_message = "Linking " + bin.short_path,
     )
     return [DefaultInfo(files = depset([bin]), executable = bin)]
 
+CarbonLibraryInfo = provider(
+    doc = "Contains information about a compiled Carbon library.",
+    fields = {
+        "api": "The api source file to provide to library consumers.",
+        "objs": "A depset of one or more compiled library files, including impl and api.",
+    },
+)
+
+def _carbon_library_impl(ctx):
+    toolchain_driver = ctx.executable.internal_exec_toolchain_driver
+    toolchain_data = ctx.files.internal_exec_toolchain_data
+
+    # If the exec driver isn't provided, that means we're trying to use a target
+    # config toolchain, likely to avoid build overhead of two configs.
+    if toolchain_driver == None:
+        toolchain_driver = ctx.executable.internal_target_toolchain_driver
+        toolchain_data = ctx.files.internal_target_toolchain_data
+
+    # Pass any C++ flags from our dependencies onto Carbon.
+    dep_flags = []
+    dep_hdrs = []
+    dep_api_srcs = []
+    for dep in ctx.attr.deps:
+        if CcInfo in dep:
+            cc_info = dep[CcInfo]
+
+            # TODO: We should reuse the feature-based flag generation in
+            # bazel/cc_toolchains here.
+            dep_flags += ["--clang-arg=-D{0}".format(define) for define in cc_info.compilation_context.defines.to_list()]
+            dep_flags += ["--clang-arg=-I{0}".format(path) for path in cc_info.compilation_context.includes.to_list()]
+            dep_flags += ["--clang-arg=-iquote{0}".format(path) for path in cc_info.compilation_context.quote_includes.to_list()]
+            dep_flags += ["--clang-arg=-isystem{0}".format(path) for path in cc_info.compilation_context.system_includes.to_list()]
+            dep_hdrs.append(cc_info.compilation_context.headers)
+        if CarbonLibraryInfo in dep:
+            carbon_info = dep[CarbonLibraryInfo]
+            dep_api_srcs.append(carbon_info.api)
+
+    # Build object files for the library impls and api file
+    srcs_and_flags = [(ctx.files.impls + ctx.files.api, dep_flags)]
+
+    objs = []
+    for (srcs, extra_flags) in srcs_and_flags:
+        for src in srcs:
+            # Build each source file. For now, we pass all sources to each compile
+            # because we don't have visibility into dependencies and have no way to
+            # specify multiple output files. Object code for each input is written
+            # into the output file in turn, so the final carbon source file
+            # specified ends up determining the contents of the object file.
+            #
+            # TODO: This is a hack; replace with something better once the toolchain
+            # supports doing so.
+            #
+            # TODO: Switch to the `prefix` based rule similar to linking when
+            # the prelude moves there.
+            out = ctx.actions.declare_file("_objs/{0}/{1}o".format(
+                ctx.label.name,
+                src.short_path.removeprefix(ctx.label.package).removesuffix(src.extension),
+            ))
+            objs.append(out)
+            srcs_reordered = dep_api_srcs + [s for s in srcs if s != src] + [src]
+            ctx.actions.run(
+                outputs = [out],
+                inputs = depset(direct = srcs_reordered, transitive = dep_hdrs),
+                executable = toolchain_driver,
+                tools = depset(toolchain_data),
+                arguments = ["compile", "--output=" + out.path, "--output-last-input-only"] +
+                            ["--no-include-carbon-core"] +
+                            extra_flags + ctx.attr.flags + [s.path for s in srcs_reordered],
+                mnemonic = "CarbonCompile",
+                progress_message = "Compiling " + src.short_path,
+            )
+
+    return [CarbonLibraryInfo(api = ctx.files.api[0], objs = depset(objs))]
+
+def _carbon_prelude_impl(ctx):
+    cc_toolchain = find_cpp_toolchain(ctx)
+
+    # TODO: find a less terrible way to figure this out
+    repo_root = str(cc_toolchain.compiler_executable)
+    repo_root = repo_root.removeprefix(cc_toolchain._crosstool_top_path + "/")
+
+    # The tool path seems to be relative to the toolchain _repository_ root, so
+    # it includes the `toolchain/install` suffix, which is why we remove it here.
+    repo_root = repo_root.removesuffix("toolchain/install/llvm/bin/clang++")
+
+    carbon_busybox = repo_root + cc_toolchain._tool_paths["carbon-busybox"]
+
+    srcs = [s for s in ctx.files.srcs if s.extension == "carbon"]
+    objs = []
+    for src in srcs:
+        out = ctx.actions.declare_file("_objs/{0}/{1}o".format(
+            ctx.label.name,
+            src.short_path.removeprefix(ctx.label.package).removesuffix(src.extension),
+        ))
+        objs.append(out)
+        srcs_reordered = [s for s in srcs if s != src] + [src]
+        ctx.actions.run(
+            outputs = [out],
+            inputs = depset(direct = srcs_reordered),
+            tools = depset(transitive = [cc_toolchain.all_files]),
+            executable = carbon_busybox,
+            arguments = ["compile", "--output=" + out.path, "--output-last-input-only"] +
+                        ["--no-prelude-import"] +
+                        [s.path for s in srcs_reordered] + ctx.attr.flags,
+            mnemonic = "CarbonPrelude",
+            progress_message = "Precompiling prelude file " + src.short_path,
+        )
+
+    return DefaultInfo(files = depset(objs))
+
+# We synthesize two sets of attributes from mirrored `select`s here
+# because we want to select on an internal property of these attributes
+# but that isn't `select`-able. Instead, we have both attributes and
+# `select` which one we use.
+_select_internal_exec_toolchain_driver = select({
+    Label("//bazel/carbon_rules:use_target_config_carbon_rules_config"): None,
+    "//conditions:default": Label("//toolchain/install:carbon-busybox"),
+})
+_select_internal_exec_toolchain_data = select({
+    Label("//bazel/carbon_rules:use_target_config_carbon_rules_config"): None,
+    "//conditions:default": Label("//toolchain/install:install_data"),
+})
+_select_internal_exec_prebuilt_runtimes = select({
+    Label("//bazel/carbon_rules:use_target_config_carbon_rules_config"): None,
+    "//conditions:default": Label("//toolchain/install:built_runtimes"),
+})
+_select_internal_target_toolchain_driver = select({
+    Label(
+        "//bazel/carbon_rules:use_target_config_carbon_rules_config",
+    ): Label("//toolchain/install:carbon-busybox"),
+    "//conditions:default": None,
+})
+_select_internal_target_toolchain_data = select({
+    Label(
+        "//bazel/carbon_rules:use_target_config_carbon_rules_config",
+    ): Label("//toolchain/install:install_data"),
+    "//conditions:default": None,
+})
+_select_internal_target_prebuilt_runtimes = select({
+    Label(
+        "//bazel/carbon_rules:use_target_config_carbon_rules_config",
+    ): Label("//toolchain/install:built_runtimes"),
+    "//conditions:default": None,
+})
+
 _carbon_binary_internal = rule(
     implementation = _carbon_binary_impl,
     attrs = {
-        "deps": attr.label_list(allow_files = True, providers = [[CcInfo]]),
+        "deps": attr.label_list(allow_files = True, providers = [[CcInfo], [CarbonLibraryInfo]]),
         "flags": attr.string_list(),
 
         # The exec config toolchain attributes. These will be `None` when using
@@ -167,14 +316,74 @@ _carbon_binary_internal = rule(
             executable = True,
             cfg = "target",
         ),
-        "prelude_srcs": attr.label_list(allow_files = [".carbon"]),
         "srcs": attr.label_list(allow_files = [".carbon"]),
         "_cc_toolchain": attr.label(default = "//toolchain/install:carbon_stage1_cc_toolchain"),
+        "_default_deps": attr.label_list(default = [Label("//core:io"), Label("//core:range")]),
     },
     executable = True,
     fragments = ["cpp"],
 )
 
+_carbon_library_internal = rule(
+    implementation = _carbon_library_impl,
+    attrs = {
+        "api": attr.label(allow_single_file = True),
+        "deps": attr.label_list(allow_files = True),
+        "flags": attr.string_list(),
+        "impls": attr.label_list(allow_files = [".carbon"]),
+
+        # The exec config toolchain attributes. These will be `None` when using
+        # the target config and populated when using the exec config. We have to
+        # use duplicate attributes here and below to have different `cfg`
+        # settings, as that isn't `select`-able, and we'll use `select`s when
+        # populating these.
+        "internal_exec_prebuilt_runtimes": attr.label(
+            cfg = "exec",
+        ),
+        "internal_exec_toolchain_data": attr.label(
+            cfg = "exec",
+        ),
+        "internal_exec_toolchain_driver": attr.label(
+            allow_single_file = True,
+            executable = True,
+            cfg = "exec",
+        ),
+
+        # The target config toolchain attributes. These will be 'None' when
+        # using the exec config and populated when using the target config. We
+        # have to use duplicate attributes here and below to have different
+        # `cfg` settings, as that isn't `select`-able, and we'll use `select`s
+        # when populating these.
+        "internal_target_prebuilt_runtimes": attr.label(
+            cfg = "target",
+        ),
+        "internal_target_toolchain_data": attr.label(
+            cfg = "target",
+        ),
+        "internal_target_toolchain_driver": attr.label(
+            allow_single_file = True,
+            executable = True,
+            cfg = "target",
+        ),
+        "_cc_toolchain": attr.label(default = "//toolchain/install:carbon_stage1_cc_toolchain"),
+    },
+    executable = False,
+    fragments = ["cpp"],
+)
+
+carbon_prelude = rule(
+    implementation = _carbon_prelude_impl,
+    attrs = {
+        "flags": attr.string_list(),
+        "srcs": attr.label_list(allow_files = [".carbon"]),
+        "_cc_toolchain": attr.label(
+            default = Label("@bazel_tools//tools/cpp:current_cc_toolchain"),
+        ),
+    },
+    toolchains = ["@bazel_tools//tools/cpp:toolchain_type"],
+    fragments = ["cpp"],
+)
+
 def carbon_binary(name, srcs, deps = [], flags = [], tags = []):
     """Compiles a Carbon binary.
 
@@ -188,43 +397,41 @@ def carbon_binary(name, srcs, deps = [], flags = [], tags = []):
     _carbon_binary_internal(
         name = name,
         srcs = srcs,
-        prelude_srcs = [Label("//core:prelude_files")],
         deps = deps,
         flags = flags,
         tags = tags,
+        internal_exec_toolchain_driver = _select_internal_exec_toolchain_driver,
+        internal_exec_toolchain_data = _select_internal_exec_toolchain_data,
+        internal_exec_prebuilt_runtimes = _select_internal_exec_prebuilt_runtimes,
+        internal_target_toolchain_driver = _select_internal_target_toolchain_driver,
+        internal_target_toolchain_data = _select_internal_target_toolchain_data,
+        internal_target_prebuilt_runtimes = _select_internal_target_prebuilt_runtimes,
+    )
 
-        # We synthesize two sets of attributes from mirrored `select`s here
-        # because we want to select on an internal property of these attributes
-        # but that isn't `select`-able. Instead, we have both attributes and
-        # `select` which one we use.
-        internal_exec_toolchain_driver = select({
-            Label("//bazel/carbon_rules:use_target_config_carbon_rules_config"): None,
-            "//conditions:default": Label("//toolchain/install:carbon-busybox"),
-        }),
-        internal_exec_toolchain_data = select({
-            Label("//bazel/carbon_rules:use_target_config_carbon_rules_config"): None,
-            "//conditions:default": Label("//toolchain/install:install_data"),
-        }),
-        internal_exec_prebuilt_runtimes = select({
-            Label("//bazel/carbon_rules:use_target_config_carbon_rules_config"): None,
-            "//conditions:default": Label("//toolchain/install:built_runtimes"),
-        }),
-        internal_target_toolchain_driver = select({
-            Label(
-                "//bazel/carbon_rules:use_target_config_carbon_rules_config",
-            ): Label("//toolchain/install:carbon-busybox"),
-            "//conditions:default": None,
-        }),
-        internal_target_toolchain_data = select({
-            Label(
-                "//bazel/carbon_rules:use_target_config_carbon_rules_config",
-            ): Label("//toolchain/install:install_data"),
-            "//conditions:default": None,
-        }),
-        internal_target_prebuilt_runtimes = select({
-            Label(
-                "//bazel/carbon_rules:use_target_config_carbon_rules_config",
-            ): Label("//toolchain/install:built_runtimes"),
-            "//conditions:default": None,
-        }),
+def carbon_library(name, api, impls = [], deps = [], flags = [], tags = [], visibility = []):
+    """Compiles a Carbon library.
+
+    Args:
+      name: The name of the build target.
+      api: Name of a single api file.
+      impls: List of zero or more implementation files.
+      deps: List of dependencies.
+      flags: Extra flags to pass to the Carbon compile command.
+      tags: Tags to apply to the rule.
+      visibility: Visibility rules for the library.
+    """
+    _carbon_library_internal(
+        name = name,
+        api = api,
+        impls = impls,
+        deps = deps,
+        flags = flags,
+        tags = tags,
+        visibility = visibility,
+        internal_exec_toolchain_driver = _select_internal_exec_toolchain_driver,
+        internal_exec_toolchain_data = _select_internal_exec_toolchain_data,
+        internal_exec_prebuilt_runtimes = _select_internal_exec_prebuilt_runtimes,
+        internal_target_toolchain_driver = _select_internal_target_toolchain_driver,
+        internal_target_toolchain_data = _select_internal_target_toolchain_data,
+        internal_target_prebuilt_runtimes = _select_internal_target_prebuilt_runtimes,
     )
diff --git a/bazel/cc_toolchains/carbon_cc_toolchain_config.bzl b/bazel/cc_toolchains/carbon_cc_toolchain_config.bzl
index 7ad1c1f41004..4061c66c90b5 100644
--- a/bazel/cc_toolchains/carbon_cc_toolchain_config.bzl
+++ b/bazel/cc_toolchains/carbon_cc_toolchain_config.bzl
@@ -11,6 +11,7 @@ load(
     "flag_group",
     "flag_set",
     "tool",
+    "tool_path",
 )
 load(
     "@rules_cc//cc:defs.bzl",
@@ -162,6 +163,7 @@ def _carbon_cc_toolchain_config_impl(ctx):
         ctx.attr.target_cpu,
         ctx.attr.target_os,
     )
+
     return cc_common.create_cc_toolchain_config_info(
         ctx = ctx,
         features = clang_cc_toolchain_features(
@@ -197,7 +199,7 @@ def _carbon_cc_toolchain_config_impl(ctx):
 
         # Pass in our tool paths to expose Make variables like $(NM) and
         # $(OBJCOPY).
-        tool_paths = llvm_tool_paths(llvm_bindir, clang_bindir),
+        tool_paths = llvm_tool_paths(llvm_bindir, clang_bindir) + [tool_path(name = "carbon-busybox", path = "carbon-busybox")],
     )
 
 carbon_cc_toolchain_config = rule(
diff --git a/core/BUILD b/core/BUILD
index 207f5f537f4e..d3d62a1bd7e1 100644
--- a/core/BUILD
+++ b/core/BUILD
@@ -2,13 +2,13 @@
 # Exceptions. See /LICENSE for license information.
 # SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
+load("//bazel/carbon_rules:defs.bzl", "carbon_library")
 load("//bazel/manifest:defs.bzl", "manifest")
 
 # Raw prelude files.
-# TODO: This includes all of Core, not just the prelude.
 filegroup(
     name = "prelude_files",
-    srcs = glob(["**/*.carbon"]),
+    srcs = ["prelude.carbon"] + glob(["prelude/**/*.carbon"]),
     visibility = ["//visibility:public"],
 )
 
@@ -29,3 +29,43 @@ filegroup(
     ],
     visibility = ["//visibility:public"],
 )
+
+filegroup(
+    name = "core_library_files",
+    srcs = glob(
+        include = ["**/*.carbon"],
+        exclude = [
+            "prelude.carbon",
+            "prelude/**",
+        ],
+    ),
+    visibility = ["//visibility:public"],
+)
+
+manifest(
+    name = "core_library_manifest.txt",
+    srcs = [":core_library_files"],
+    strip_package_dir = True,
+)
+
+filegroup(
+    name = "core_library",
+    srcs = [
+        ":core_library_files",
+        ":core_library_manifest.txt",
+    ],
+    visibility = ["//visibility:public"],
+)
+
+carbon_library(
+    name = "io",
+    api = "io.carbon",
+    impls = ["io.impl.carbon"],
+    visibility = ["//visibility:public"],
+)
+
+carbon_library(
+    name = "range",
+    api = "range.carbon",
+    visibility = ["//visibility:public"],
+)
diff --git a/core/io.carbon b/core/io.carbon
index 8a916d06b029..fff6cfe806f0 100644
--- a/core/io.carbon
+++ b/core/io.carbon
@@ -7,24 +7,15 @@
 
 package Core library "io";
 
-import library "prelude";
-
 // TODO: Support printing other types.
 // TODO: Consider rewriting using native support once library support exists.
 fn Print(x: i32) = "print.int";
 fn PrintChar(x: char) -> i32 = "print.char";
 
-fn PrintStr(msg: str) {
-  let size: i64 = msg.Size() as i64;
-  var i: i64 = 0;
-  while (i < size) {
-    PrintChar(msg[i]);
-    ++i;
-  }
-}
+fn PrintStr(msg: str);
 
 // TODO: Return an `Optional(char)` instead of `i32`.
 fn ReadChar() -> i32 = "read.char";
 
 // TODO: Change this to a global constant once they are fully supported.
-fn EOF() -> i32 { return -1; }
+fn EOF() -> i32;
diff --git a/core/io.impl.carbon b/core/io.impl.carbon
new file mode 100644
index 000000000000..99faa0b96d3a
--- /dev/null
+++ b/core/io.impl.carbon
@@ -0,0 +1,20 @@
+// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
+// Exceptions. See /LICENSE for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+// TODO: This library is not part of the design. Either write a matching
+// proposal or remove this.
+
+impl package Core library "io";
+
+fn PrintStr(msg: str) {
+  let size: i64 = msg.Size() as i64;
+  var i: i64 = 0;
+  while (i < size) {
+    PrintChar(msg[i]);
+    ++i;
+  }
+}
+
+// TODO: Change this to a global constant once they are fully supported.
+fn EOF() -> i32 { return -1; }
diff --git a/core/range.carbon b/core/range.carbon
index 55b9de15eef4..299f83267307 100644
--- a/core/range.carbon
+++ b/core/range.carbon
@@ -7,15 +7,6 @@
 
 package Core library "range";
 
-import library "prelude/destroy";
-import library "prelude/iterate";
-import library "prelude/operators/arithmetic";
-import library "prelude/operators/as";
-import library "prelude/operators/comparison";
-import library "prelude/types/int";
-import library "prelude/types/int_literal";
-import library "prelude/types/optional";
-
 class IntRange(N: IntLiteral) {
   fn Make(start: Int(N), end: Int(N)) -> Self {
     return {.start = start, .end = end};
diff --git a/toolchain/base/install_paths.cpp b/toolchain/base/install_paths.cpp
index 130eee603032..9689be526a49 100644
--- a/toolchain/base/install_paths.cpp
+++ b/toolchain/base/install_paths.cpp
@@ -86,6 +86,11 @@ auto InstallPaths::ReadClangHeadersManifest() const
   return ReadManifest(root_, "clang_headers_manifest.txt");
 }
 
+auto InstallPaths::ReadCarbonCoreManifest() const
+    -> ErrorOr<llvm::SmallVector<std::string>> {
+  return ReadManifest(core_package(), "core_library_manifest.txt");
+}
+
 auto InstallPaths::ReadManifest(std::filesystem::path manifest_path,
                                 std::filesystem::path manifest_file) const
     -> ErrorOr<llvm::SmallVector<std::string>> {
diff --git a/toolchain/base/install_paths.h b/toolchain/base/install_paths.h
index efb73830dfd4..1a225654d520 100644
--- a/toolchain/base/install_paths.h
+++ b/toolchain/base/install_paths.h
@@ -81,6 +81,11 @@ class InstallPaths {
   auto ReadClangHeadersManifest() const
       -> ErrorOr<llvm::SmallVector<std::string>>;
 
+  // Returns the contents of the core library manifest file. This is the list
+  // of Carbon source files in the Carbon Core library, excluding the prelude.
+  auto ReadCarbonCoreManifest() const
+      -> ErrorOr<llvm::SmallVector<std::string>>;
+
   // Check for an error detecting the install paths correctly.
   //
   // A nullopt return means no errors encountered and the paths should work
diff --git a/toolchain/base/runtimes_build_info.bzl b/toolchain/base/runtimes_build_info.bzl
index 06501ed84e5a..44dc46f1bc44 100644
--- a/toolchain/base/runtimes_build_info.bzl
+++ b/toolchain/base/runtimes_build_info.bzl
@@ -25,6 +25,10 @@ load("@llvm-project//libcxx:libcxx_library.bzl", "libcxx_and_abi_copts")
 load("@llvm-project//libunwind:libunwind_library.bzl", "libunwind_copts")
 load("//bazel/cc_rules:defs.bzl", "cc_library")
 
+CARBON_CORE_SRCS_FILEGROUPS = [
+    "//core:prelude_files",
+]
+
 CRT_FILES = {
     "crtbegin_src": "@llvm-project//compiler-rt:builtins_crtbegin_src",
     "crtend_src": "@llvm-project//compiler-rt:builtins_crtend_src",
@@ -72,6 +76,7 @@ RUNTIMES_PREFIXES = {
     "libcxxabi_textual_srcs": "runtimes/libcxxabi/",
     "libunwind_hdrs": "runtimes/libunwind/",
     "libunwind_srcs": "runtimes/libunwind/",
+    "prelude_files": "core/",
 }
 
 def _get_name(target):
@@ -143,6 +148,7 @@ def _get_substitutions(ctx):
             RUNTIMES_PREFIXES[name],
         )
         for name in [_get_name(g) for g in (
+            CARBON_CORE_SRCS_FILEGROUPS +
             RUNTIMES_HDRS_FILEGROUPS + RUNTIMES_SRCS_FILEGROUPS +
             RUNTIMES_TEXTUAL_SRCS_FILEGROUPS
         )]
@@ -154,6 +160,7 @@ _common_runtimes_rule_attrs = {
 } | {
     "_" + _get_name(g): attr.label_list(default = [g], allow_files = True)
     for g in (
+        CARBON_CORE_SRCS_FILEGROUPS +
         BUILTINS_SRCS_FILEGROUPS +
         BUILTINS_TEXTUAL_SRCS_FILEGROUPS +
         RUNTIMES_HDRS_FILEGROUPS +
diff --git a/toolchain/base/runtimes_build_info.tpl.h b/toolchain/base/runtimes_build_info.tpl.h
index 10203f2e8b25..0f543400f0e0 100644
--- a/toolchain/base/runtimes_build_info.tpl.h
+++ b/toolchain/base/runtimes_build_info.tpl.h
@@ -40,6 +40,8 @@ inline constexpr llvm::StringLiteral LibcxxCopts[] = {LIBCXX_AND_ABI_COPTS};
 inline constexpr llvm::StringLiteral LibunwindSrcs[] = {LIBUNWIND_SRCS};
 inline constexpr llvm::StringLiteral LibunwindCopts[] = {LIBUNWIND_COPTS};
 
+inline constexpr llvm::StringLiteral CarbonCorePreludeSrcs[] = {PRELUDE_FILES};
+
 }  // namespace Carbon::RuntimesBuildInfo
 
 #endif  // CARBON_TOOLCHAIN_BASE_RUNTIMES_BUILD_INFO_TPL_H_
diff --git a/toolchain/base/runtimes_build_vars.tpl.bzl b/toolchain/base/runtimes_build_vars.tpl.bzl
index f94e0d34d406..1ee14ef515fc 100644
--- a/toolchain/base/runtimes_build_vars.tpl.bzl
+++ b/toolchain/base/runtimes_build_vars.tpl.bzl
@@ -43,3 +43,5 @@ libunwind_hdrs = [LIBUNWIND_HDRS]
 libunwind_srcs = [LIBUNWIND_SRCS]
 
 libunwind_copts = [LIBUNWIND_COPTS]
+
+carbon_core_srcs = [PRELUDE_FILES]
diff --git a/toolchain/benchmarking/compile_benchmark.cpp b/toolchain/benchmarking/compile_benchmark.cpp
index 878f7487f54e..5890607de483 100644
--- a/toolchain/benchmarking/compile_benchmark.cpp
+++ b/toolchain/benchmarking/compile_benchmark.cpp
@@ -116,7 +116,9 @@ class InProcessCompiler {
 
   auto RunCompile(llvm::StringRef file_name, Phase phase) -> bool {
     if constexpr (L == Lang::Carbon) {
-      return driver_->RunCommand({"compile", PhaseFlag(phase), file_name})
+      return driver_
+          ->RunCommand({"compile", PhaseFlag(phase), "--no-include-carbon-core",
+                        file_name})
           .success;
     }
 
@@ -204,7 +206,8 @@ class SubprocessCompiler {
 
     if constexpr (L == Lang::Carbon) {
       program = carbon_path_;
-      args = {"carbon", "compile", PhaseFlag(phase), file_name};
+      args = {"carbon", "compile", PhaseFlag(phase), "--no-include-carbon-core",
+              file_name};
     } else {
       program = clang_path_;
       args = {"clang++", "--driver-mode=g++"};
diff --git a/toolchain/benchmarking/prelude_benchmark.cpp b/toolchain/benchmarking/prelude_benchmark.cpp
index 44625a1922cc..ebfe589e59d5 100644
--- a/toolchain/benchmarking/prelude_benchmark.cpp
+++ b/toolchain/benchmarking/prelude_benchmark.cpp
@@ -102,7 +102,9 @@ class PreludeCompileBenchmark {
     if (mem_usage) {
       driver.set_mem_usage(mem_usage);
     }
-    return driver.RunCommand({"compile", "--phase=check", InputFileName})
+    return driver
+        .RunCommand({"compile", "--phase=check", "--no-include-carbon-core",
+                     InputFileName})
         .success;
   }
 
diff --git a/toolchain/benchmarking/source_gen_test.cpp b/toolchain/benchmarking/source_gen_test.cpp
index f73c104f2692..b98b9f37421c 100644
--- a/toolchain/benchmarking/source_gen_test.cpp
+++ b/toolchain/benchmarking/source_gen_test.cpp
@@ -242,7 +242,10 @@ auto TestCompile(llvm::StringRef source) -> bool {
 
   fs->addFile("test.carbon", /*ModificationTime=*/0,
               llvm::MemoryBuffer::getMemBuffer(source));
-  return driver.RunCommand({"compile", "--phase=check", "test.carbon"}).success;
+  return driver
+      .RunCommand({"compile", "--phase=check", "--no-include-carbon-core",
+                   "test.carbon"})
+      .success;
 }
 
 TEST(SourceGenTest, GenApiFileDenseDeclsTest) {
diff --git a/toolchain/check/check.cpp b/toolchain/check/check.cpp
index a52f32aab27c..9f236caadd16 100644
--- a/toolchain/check/check.cpp
+++ b/toolchain/check/check.cpp
@@ -458,13 +458,25 @@ auto CheckParseTrees(
 
     // Add the prelude import. It's added to explicit_import_map so that it can
     // conflict with an explicit import of the prelude.
+    // We add the prelude to every Carbon unit except for the prelude itself.
     if (options.prelude_import &&
-        !(packaging && packaging->names.package_id == PackageNameId::Core)) {
+        (!packaging || packaging->names.package_id != PackageNameId::Core ||
+         packaging->names.library_id == StringLiteralValueId::None ||
+         !unit_info.unit->value_stores->string_literal_values()
+              .Get(packaging->names.library_id)
+              .starts_with("prelude"))) {
       auto prelude_id =
           unit_info.unit->value_stores->string_literal_values().Add("prelude");
+      // Adding the prelude to the non-prelude parts of Core requires different
+      // semantics because it is not valid to mention the name of the package
+      // for a library import from the same package.
+      auto package_id =
+          (packaging && packaging->names.package_id == PackageNameId::Core)
+              ? PackageNameId::None
+              : PackageNameId::Core;
       TrackImport(api_map, &explicit_import_map, unit_info,
                   {.node_id = Parse::NoneNodeId(),
-                   .package_id = PackageNameId::Core,
+                   .package_id = package_id,
                    .library_id = prelude_id},
                   options.fuzzing);
     }
diff --git a/toolchain/check/testdata/basics/verbose.carbon b/toolchain/check/testdata/basics/verbose.carbon
index 55343d8e964f..16632e50d276 100644
--- a/toolchain/check/testdata/basics/verbose.carbon
+++ b/toolchain/check/testdata/basics/verbose.carbon
@@ -3,7 +3,7 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // INCLUDE-FILE: toolchain/testing/testdata/min_prelude/none.carbon
-// ARGS: -v compile --phase=check %s
+// ARGS: -v compile --phase=check --no-include-carbon-core %s
 //
 // Only checks a couple statements in order to minimize manual update churn.
 // To test this file alone, run:
diff --git a/toolchain/check/testdata/builtins/print/char.carbon b/toolchain/check/testdata/builtins/print/char.carbon
index 3840357d68e1..733095e3350a 100644
--- a/toolchain/check/testdata/builtins/print/char.carbon
+++ b/toolchain/check/testdata/builtins/print/char.carbon
@@ -2,6 +2,7 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
+// EXTRA-ARGS: --include-carbon-core
 // INCLUDE-FILE: toolchain/testing/testdata/min_prelude/full.carbon
 //
 // AUTOUPDATE
@@ -29,7 +30,7 @@ fn Main() {
 // CHECK:STDOUT:   %Int.type: type = generic_class_type @Int [concrete]
 // CHECK:STDOUT:   %Int.generic: %Int.type = struct_value () [concrete]
 // CHECK:STDOUT:   %i32: type = class_type @Int, @Int(%int_32) [concrete]
-// CHECK:STDOUT:   %PrintChar.type.7a7: type = fn_type @PrintChar.loc15 [concrete]
+// CHECK:STDOUT:   %PrintChar.type.7a7: type = fn_type @PrintChar.loc16 [concrete]
 // CHECK:STDOUT:   %PrintChar.772: %PrintChar.type.7a7 = struct_value () [concrete]
 // CHECK:STDOUT:   %.75c: Core.CharLiteral = char_value U+0031 [concrete]
 // CHECK:STDOUT:   %ImplicitAs.type.0ff: type = generic_interface_type @ImplicitAs [concrete]
@@ -70,23 +71,23 @@ fn Main() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @Main() {
 // CHECK:STDOUT: !entry:
-// CHECK:STDOUT:   %PrintChar.ref.loc19: %PrintChar.type.7a7 = name_ref PrintChar, file.%PrintChar.decl [concrete = constants.%PrintChar.772]
-// CHECK:STDOUT:   %.loc19_13.1: Core.CharLiteral = char_value U+0031 [concrete = constants.%.75c]
-// CHECK:STDOUT:   %impl.elem0.loc19: %.1e6 = impl_witness_access constants.%ImplicitAs.impl_witness.780, element0 [concrete = constants.%Core.CharLiteral.as.ImplicitAs.impl.Convert]
-// CHECK:STDOUT:   %bound_method.loc19: <bound method> = bound_method %.loc19_13.1, %impl.elem0.loc19 [concrete = constants.%Core.CharLiteral.as.ImplicitAs.impl.Convert.bound.17b]
-// CHECK:STDOUT:   %Core.CharLiteral.as.ImplicitAs.impl.Convert.call.loc19: init %char = call %bound_method.loc19(%.loc19_13.1) [concrete = constants.%int_49]
-// CHECK:STDOUT:   %.loc19_13.2: %char = value_of_initializer %Core.CharLiteral.as.ImplicitAs.impl.Convert.call.loc19 [concrete = constants.%int_49]
-// CHECK:STDOUT:   %.loc19_13.3: %char = converted %.loc19_13.1, %.loc19_13.2 [concrete = constants.%int_49]
-// CHECK:STDOUT:   %PrintChar.call.loc19: init %i32 = call %PrintChar.ref.loc19(%.loc19_13.3)
-// CHECK:STDOUT:   %Core.ref: <namespace> = name_ref Core, imports.%Core [concrete = imports.%Core]
-// CHECK:STDOUT:   %PrintChar.ref.loc20: %PrintChar.type.b3c = name_ref PrintChar, imports.%Core.PrintChar [concrete = constants.%PrintChar.063]
-// CHECK:STDOUT:   %.loc20_18.1: Core.CharLiteral = char_value U+0032 [concrete = constants.%.f8d]
+// CHECK:STDOUT:   %PrintChar.ref.loc20: %PrintChar.type.7a7 = name_ref PrintChar, file.%PrintChar.decl [concrete = constants.%PrintChar.772]
+// CHECK:STDOUT:   %.loc20_13.1: Core.CharLiteral = char_value U+0031 [concrete = constants.%.75c]
 // CHECK:STDOUT:   %impl.elem0.loc20: %.1e6 = impl_witness_access constants.%ImplicitAs.impl_witness.780, element0 [concrete = constants.%Core.CharLiteral.as.ImplicitAs.impl.Convert]
-// CHECK:STDOUT:   %bound_method.loc20: <bound method> = bound_method %.loc20_18.1, %impl.elem0.loc20 [concrete = constants.%Core.CharLiteral.as.ImplicitAs.impl.Convert.bound.e67]
-// CHECK:STDOUT:   %Core.CharLiteral.as.ImplicitAs.impl.Convert.call.loc20: init %char = call %bound_method.loc20(%.loc20_18.1) [concrete = constants.%int_50]
-// CHECK:STDOUT:   %.loc20_18.2: %char = value_of_initializer %Core.CharLiteral.as.ImplicitAs.impl.Convert.call.loc20 [concrete = constants.%int_50]
-// CHECK:STDOUT:   %.loc20_18.3: %char = converted %.loc20_18.1, %.loc20_18.2 [concrete = constants.%int_50]
-// CHECK:STDOUT:   %PrintChar.call.loc20: init %i32 = call %PrintChar.ref.loc20(%.loc20_18.3)
+// CHECK:STDOUT:   %bound_method.loc20: <bound method> = bound_method %.loc20_13.1, %impl.elem0.loc20 [concrete = constants.%Core.CharLiteral.as.ImplicitAs.impl.Convert.bound.17b]
+// CHECK:STDOUT:   %Core.CharLiteral.as.ImplicitAs.impl.Convert.call.loc20: init %char = call %bound_method.loc20(%.loc20_13.1) [concrete = constants.%int_49]
+// CHECK:STDOUT:   %.loc20_13.2: %char = value_of_initializer %Core.CharLiteral.as.ImplicitAs.impl.Convert.call.loc20 [concrete = constants.%int_49]
+// CHECK:STDOUT:   %.loc20_13.3: %char = converted %.loc20_13.1, %.loc20_13.2 [concrete = constants.%int_49]
+// CHECK:STDOUT:   %PrintChar.call.loc20: init %i32 = call %PrintChar.ref.loc20(%.loc20_13.3)
+// CHECK:STDOUT:   %Core.ref: <namespace> = name_ref Core, imports.%Core [concrete = imports.%Core]
+// CHECK:STDOUT:   %PrintChar.ref.loc21: %PrintChar.type.b3c = name_ref PrintChar, imports.%Core.PrintChar [concrete = constants.%PrintChar.063]
+// CHECK:STDOUT:   %.loc21_18.1: Core.CharLiteral = char_value U+0032 [concrete = constants.%.f8d]
+// CHECK:STDOUT:   %impl.elem0.loc21: %.1e6 = impl_witness_access constants.%ImplicitAs.impl_witness.780, element0 [concrete = constants.%Core.CharLiteral.as.ImplicitAs.impl.Convert]
+// CHECK:STDOUT:   %bound_method.loc21: <bound method> = bound_method %.loc21_18.1, %impl.elem0.loc21 [concrete = constants.%Core.CharLiteral.as.ImplicitAs.impl.Convert.bound.e67]
+// CHECK:STDOUT:   %Core.CharLiteral.as.ImplicitAs.impl.Convert.call.loc21: init %char = call %bound_method.loc21(%.loc21_18.1) [concrete = constants.%int_50]
+// CHECK:STDOUT:   %.loc21_18.2: %char = value_of_initializer %Core.CharLiteral.as.ImplicitAs.impl.Convert.call.loc21 [concrete = constants.%int_50]
+// CHECK:STDOUT:   %.loc21_18.3: %char = converted %.loc21_18.1, %.loc21_18.2 [concrete = constants.%int_50]
+// CHECK:STDOUT:   %PrintChar.call.loc21: init %i32 = call %PrintChar.ref.loc21(%.loc21_18.3)
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/builtins/print/int.carbon b/toolchain/check/testdata/builtins/print/int.carbon
index 676b7aaead4f..733ad72be824 100644
--- a/toolchain/check/testdata/builtins/print/int.carbon
+++ b/toolchain/check/testdata/builtins/print/int.carbon
@@ -2,6 +2,7 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
+// EXTRA-ARGS: --include-carbon-core
 // INCLUDE-FILE: toolchain/testing/testdata/min_prelude/full.carbon
 //
 // AUTOUPDATE
@@ -29,7 +30,7 @@ fn Main() {
 // CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
 // CHECK:STDOUT:   %Int.generic: %Int.type = struct_value () [concrete]
 // CHECK:STDOUT:   %i32: type = class_type @Int, @Int(%int_32) [concrete]
-// CHECK:STDOUT:   %Print.type.009: type = fn_type @Print.loc15 [concrete]
+// CHECK:STDOUT:   %Print.type.009: type = fn_type @Print.loc16 [concrete]
 // CHECK:STDOUT:   %Print.9c5: %Print.type.009 = struct_value () [concrete]
 // CHECK:STDOUT:   %int_1.5b8: Core.IntLiteral = int_value 1 [concrete]
 // CHECK:STDOUT:   %ImplicitAs.type.0ff: type = generic_interface_type @ImplicitAs [concrete]
@@ -74,27 +75,27 @@ fn Main() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @Main() {
 // CHECK:STDOUT: !entry:
-// CHECK:STDOUT:   %Print.ref.loc19: %Print.type.009 = name_ref Print, file.%Print.decl [concrete = constants.%Print.9c5]
+// CHECK:STDOUT:   %Print.ref.loc20: %Print.type.009 = name_ref Print, file.%Print.decl [concrete = constants.%Print.9c5]
 // CHECK:STDOUT:   %int_1: Core.IntLiteral = int_value 1 [concrete = constants.%int_1.5b8]
-// CHECK:STDOUT:   %impl.elem0.loc19: %.1c5 = impl_witness_access constants.%ImplicitAs.impl_witness.a23, element0 [concrete = constants.%Core.IntLiteral.as.ImplicitAs.impl.Convert.e39]
-// CHECK:STDOUT:   %bound_method.loc19_9.1: <bound method> = bound_method %int_1, %impl.elem0.loc19 [concrete = constants.%Core.IntLiteral.as.ImplicitAs.impl.Convert.bound.094]
-// CHECK:STDOUT:   %specific_fn.loc19: <specific function> = specific_function %impl.elem0.loc19, @Core.IntLiteral.as.ImplicitAs.impl.Convert(constants.%int_32) [concrete = constants.%Core.IntLiteral.as.ImplicitAs.impl.Convert.specific_fn]
-// CHECK:STDOUT:   %bound_method.loc19_9.2: <bound method> = bound_method %int_1, %specific_fn.loc19 [concrete = constants.%bound_method.953]
-// CHECK:STDOUT:   %Core.IntLiteral.as.ImplicitAs.impl.Convert.call.loc19: init %i32 = call %bound_method.loc19_9.2(%int_1) [concrete = constants.%int_1.0c6]
-// CHECK:STDOUT:   %.loc19_9.1: %i32 = value_of_initializer %Core.IntLiteral.as.ImplicitAs.impl.Convert.call.loc19 [concrete = constants.%int_1.0c6]
-// CHECK:STDOUT:   %.loc19_9.2: %i32 = converted %int_1, %.loc19_9.1 [concrete = constants.%int_1.0c6]
-// CHECK:STDOUT:   %Print.call.loc19: init %empty_tuple.type = call %Print.ref.loc19(%.loc19_9.2)
-// CHECK:STDOUT:   %Core.ref: <namespace> = name_ref Core, imports.%Core [concrete = imports.%Core]
-// CHECK:STDOUT:   %Print.ref.loc20: %Print.type.4a7 = name_ref Print, imports.%Core.Print [concrete = constants.%Print.d24]
-// CHECK:STDOUT:   %int_2: Core.IntLiteral = int_value 2 [concrete = constants.%int_2.ecc]
 // CHECK:STDOUT:   %impl.elem0.loc20: %.1c5 = impl_witness_access constants.%ImplicitAs.impl_witness.a23, element0 [concrete = constants.%Core.IntLiteral.as.ImplicitAs.impl.Convert.e39]
-// CHECK:STDOUT:   %bound_method.loc20_14.1: <bound method> = bound_method %int_2, %impl.elem0.loc20 [concrete = constants.%Core.IntLiteral.as.ImplicitAs.impl.Convert.bound.9f3]
+// CHECK:STDOUT:   %bound_method.loc20_9.1: <bound method> = bound_method %int_1, %impl.elem0.loc20 [concrete = constants.%Core.IntLiteral.as.ImplicitAs.impl.Convert.bound.094]
 // CHECK:STDOUT:   %specific_fn.loc20: <specific function> = specific_function %impl.elem0.loc20, @Core.IntLiteral.as.ImplicitAs.impl.Convert(constants.%int_32) [concrete = constants.%Core.IntLiteral.as.ImplicitAs.impl.Convert.specific_fn]
-// CHECK:STDOUT:   %bound_method.loc20_14.2: <bound method> = bound_method %int_2, %specific_fn.loc20 [concrete = constants.%bound_method.3cb]
-// CHECK:STDOUT:   %Core.IntLiteral.as.ImplicitAs.impl.Convert.call.loc20: init %i32 = call %bound_method.loc20_14.2(%int_2) [concrete = constants.%int_2.295]
-// CHECK:STDOUT:   %.loc20_14.1: %i32 = value_of_initializer %Core.IntLiteral.as.ImplicitAs.impl.Convert.call.loc20 [concrete = constants.%int_2.295]
-// CHECK:STDOUT:   %.loc20_14.2: %i32 = converted %int_2, %.loc20_14.1 [concrete = constants.%int_2.295]
-// CHECK:STDOUT:   %Print.call.loc20: init %empty_tuple.type = call %Print.ref.loc20(%.loc20_14.2)
+// CHECK:STDOUT:   %bound_method.loc20_9.2: <bound method> = bound_method %int_1, %specific_fn.loc20 [concrete = constants.%bound_method.953]
+// CHECK:STDOUT:   %Core.IntLiteral.as.ImplicitAs.impl.Convert.call.loc20: init %i32 = call %bound_method.loc20_9.2(%int_1) [concrete = constants.%int_1.0c6]
+// CHECK:STDOUT:   %.loc20_9.1: %i32 = value_of_initializer %Core.IntLiteral.as.ImplicitAs.impl.Convert.call.loc20 [concrete = constants.%int_1.0c6]
+// CHECK:STDOUT:   %.loc20_9.2: %i32 = converted %int_1, %.loc20_9.1 [concrete = constants.%int_1.0c6]
+// CHECK:STDOUT:   %Print.call.loc20: init %empty_tuple.type = call %Print.ref.loc20(%.loc20_9.2)
+// CHECK:STDOUT:   %Core.ref: <namespace> = name_ref Core, imports.%Core [concrete = imports.%Core]
+// CHECK:STDOUT:   %Print.ref.loc21: %Print.type.4a7 = name_ref Print, imports.%Core.Print [concrete = constants.%Print.d24]
+// CHECK:STDOUT:   %int_2: Core.IntLiteral = int_value 2 [concrete = constants.%int_2.ecc]
+// CHECK:STDOUT:   %impl.elem0.loc21: %.1c5 = impl_witness_access constants.%ImplicitAs.impl_witness.a23, element0 [concrete = constants.%Core.IntLiteral.as.ImplicitAs.impl.Convert.e39]
+// CHECK:STDOUT:   %bound_method.loc21_14.1: <bound method> = bound_method %int_2, %impl.elem0.loc21 [concrete = constants.%Core.IntLiteral.as.ImplicitAs.impl.Convert.bound.9f3]
+// CHECK:STDOUT:   %specific_fn.loc21: <specific function> = specific_function %impl.elem0.loc21, @Core.IntLiteral.as.ImplicitAs.impl.Convert(constants.%int_32) [concrete = constants.%Core.IntLiteral.as.ImplicitAs.impl.Convert.specific_fn]
+// CHECK:STDOUT:   %bound_method.loc21_14.2: <bound method> = bound_method %int_2, %specific_fn.loc21 [concrete = constants.%bound_method.3cb]
+// CHECK:STDOUT:   %Core.IntLiteral.as.ImplicitAs.impl.Convert.call.loc21: init %i32 = call %bound_method.loc21_14.2(%int_2) [concrete = constants.%int_2.295]
+// CHECK:STDOUT:   %.loc21_14.1: %i32 = value_of_initializer %Core.IntLiteral.as.ImplicitAs.impl.Convert.call.loc21 [concrete = constants.%int_2.295]
+// CHECK:STDOUT:   %.loc21_14.2: %i32 = converted %int_2, %.loc21_14.1 [concrete = constants.%int_2.295]
+// CHECK:STDOUT:   %Print.call.loc21: init %empty_tuple.type = call %Print.ref.loc21(%.loc21_14.2)
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/builtins/read/char.carbon b/toolchain/check/testdata/builtins/read/char.carbon
index b75d9740025c..40f293311d38 100644
--- a/toolchain/check/testdata/builtins/read/char.carbon
+++ b/toolchain/check/testdata/builtins/read/char.carbon
@@ -2,6 +2,7 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
+// EXTRA-ARGS: --include-carbon-core
 // INCLUDE-FILE: toolchain/testing/testdata/min_prelude/full.carbon
 //
 // AUTOUPDATE
diff --git a/toolchain/check/testdata/impl/interface_args.carbon b/toolchain/check/testdata/impl/interface_args.carbon
index bf16b075955f..c29dc563dc60 100644
--- a/toolchain/check/testdata/impl/interface_args.carbon
+++ b/toolchain/check/testdata/impl/interface_args.carbon
@@ -134,10 +134,16 @@ fn InstanceC(a: A) -> C {
 // CHECK:STDOUT:   %assoc0: %ImplicitAs.assoc_type = assoc_entity element0, @ImplicitAs.WithSelf.%ImplicitAs.WithSelf.Convert.decl [symbolic]
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
+// CHECK:STDOUT: imports {
+// CHECK:STDOUT:   %Core.Destroy = import_ref Core//prelude/parts/destroy, Destroy, unloaded
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
 // CHECK:STDOUT: file {
 // CHECK:STDOUT:   package: <namespace> = namespace [concrete] {
+// CHECK:STDOUT:     .Destroy = imports.%Core.Destroy
 // CHECK:STDOUT:     .ImplicitAs = %ImplicitAs.decl
 // CHECK:STDOUT:   }
+// CHECK:STDOUT:   %default.import = import <none>
 // CHECK:STDOUT:   %ImplicitAs.decl: %ImplicitAs.type.0ff = interface_decl @ImplicitAs [concrete = constants.%ImplicitAs.generic] {
 // CHECK:STDOUT:     %Dest.patt.loc3_26.1: %pattern_type.98f = symbolic_binding_pattern Dest, 0 [symbolic = %Dest.patt.loc3_26.2 (constants.%Dest.patt)]
 // CHECK:STDOUT:   } {
diff --git a/toolchain/check/testdata/operators/overloaded/index.carbon b/toolchain/check/testdata/operators/overloaded/index.carbon
index 955a5e6210f0..6d9f3c05e83f 100644
--- a/toolchain/check/testdata/operators/overloaded/index.carbon
+++ b/toolchain/check/testdata/operators/overloaded/index.carbon
@@ -84,10 +84,32 @@ fn F() {
 // CHECK:STDOUT:   %complete_type: <witness> = complete_type_witness %empty_struct_type [concrete]
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
+// CHECK:STDOUT: imports {
+// CHECK:STDOUT:   %Core.UnsafeAs = import_ref Core//prelude/parts/as, UnsafeAs, unloaded
+// CHECK:STDOUT:   %Core.As = import_ref Core//prelude/parts/as, As, unloaded
+// CHECK:STDOUT:   %Core.ImplicitAs = import_ref Core//prelude/parts/as, ImplicitAs, unloaded
+// CHECK:STDOUT:   %Core.BitAndWith = import_ref Core//prelude/parts/as, BitAndWith, unloaded
+// CHECK:STDOUT:   %Core.Copy = import_ref Core//prelude/parts/copy, Copy, unloaded
+// CHECK:STDOUT:   %Core.DefaultOrUnformed = import_ref Core//prelude/parts/default, DefaultOrUnformed, unloaded
+// CHECK:STDOUT:   %Core.Default = import_ref Core//prelude/parts/default, Default, unloaded
+// CHECK:STDOUT:   %Core.Destroy = import_ref Core//prelude/parts/destroy, Destroy, unloaded
+// CHECK:STDOUT:   %Core.Form = import_ref Core//prelude/parts/form, Form, unloaded
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
 // CHECK:STDOUT: file {
 // CHECK:STDOUT:   package: <namespace> = namespace [concrete] {
+// CHECK:STDOUT:     .UnsafeAs = imports.%Core.UnsafeAs
+// CHECK:STDOUT:     .As = imports.%Core.As
+// CHECK:STDOUT:     .ImplicitAs = imports.%Core.ImplicitAs
+// CHECK:STDOUT:     .BitAndWith = imports.%Core.BitAndWith
+// CHECK:STDOUT:     .Copy = imports.%Core.Copy
+// CHECK:STDOUT:     .DefaultOrUnformed = imports.%Core.DefaultOrUnformed
+// CHECK:STDOUT:     .Default = imports.%Core.Default
+// CHECK:STDOUT:     .Destroy = imports.%Core.Destroy
+// CHECK:STDOUT:     .Form = imports.%Core.Form
 // CHECK:STDOUT:     .IndexWith = %IndexWith.decl
 // CHECK:STDOUT:   }
+// CHECK:STDOUT:   %default.import = import <none>
 // CHECK:STDOUT:   %IndexWith.decl: type = class_decl @IndexWith [concrete = constants.%IndexWith] {} {}
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
@@ -210,10 +232,32 @@ fn F() {
 // CHECK:STDOUT:   %assoc0: %IndexWith.assoc_type = assoc_entity element0, @IndexWith.WithSelf.%IndexWith.WithSelf.At.decl [symbolic]
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
+// CHECK:STDOUT: imports {
+// CHECK:STDOUT:   %Core.UnsafeAs = import_ref Core//prelude/parts/as, UnsafeAs, unloaded
+// CHECK:STDOUT:   %Core.As = import_ref Core//prelude/parts/as, As, unloaded
+// CHECK:STDOUT:   %Core.ImplicitAs = import_ref Core//prelude/parts/as, ImplicitAs, unloaded
+// CHECK:STDOUT:   %Core.BitAndWith = import_ref Core//prelude/parts/as, BitAndWith, unloaded
+// CHECK:STDOUT:   %Core.Copy = import_ref Core//prelude/parts/copy, Copy, unloaded
+// CHECK:STDOUT:   %Core.DefaultOrUnformed = import_ref Core//prelude/parts/default, DefaultOrUnformed, unloaded
+// CHECK:STDOUT:   %Core.Default = import_ref Core//prelude/parts/default, Default, unloaded
+// CHECK:STDOUT:   %Core.Destroy = import_ref Core//prelude/parts/destroy, Destroy, unloaded
+// CHECK:STDOUT:   %Core.Form = import_ref Core//prelude/parts/form, Form, unloaded
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
 // CHECK:STDOUT: file {
 // CHECK:STDOUT:   package: <namespace> = namespace [concrete] {
+// CHECK:STDOUT:     .UnsafeAs = imports.%Core.UnsafeAs
+// CHECK:STDOUT:     .As = imports.%Core.As
+// CHECK:STDOUT:     .ImplicitAs = imports.%Core.ImplicitAs
+// CHECK:STDOUT:     .BitAndWith = imports.%Core.BitAndWith
+// CHECK:STDOUT:     .Copy = imports.%Core.Copy
+// CHECK:STDOUT:     .DefaultOrUnformed = imports.%Core.DefaultOrUnformed
+// CHECK:STDOUT:     .Default = imports.%Core.Default
+// CHECK:STDOUT:     .Destroy = imports.%Core.Destroy
+// CHECK:STDOUT:     .Form = imports.%Core.Form
 // CHECK:STDOUT:     .IndexWith = %IndexWith.decl
 // CHECK:STDOUT:   }
+// CHECK:STDOUT:   %default.import = import <none>
 // CHECK:STDOUT:   %IndexWith.decl: %IndexWith.type.df6 = interface_decl @IndexWith [concrete = constants.%IndexWith.generic] {
 // CHECK:STDOUT:     %SubscriptType.patt.loc4_34.1: %pattern_type.98f = symbolic_binding_pattern SubscriptType, 0 [symbolic = %SubscriptType.patt.loc4_34.2 (constants.%SubscriptType.patt)]
 // CHECK:STDOUT:     %ElementType.patt.loc4_53.1: %pattern_type.98f = symbolic_binding_pattern ElementType, 1 [symbolic = %ElementType.patt.loc4_53.2 (constants.%ElementType.patt)]
diff --git a/toolchain/diagnostics/coverage_test.cpp b/toolchain/diagnostics/coverage_test.cpp
index e59ddeffd71f..3409283916e2 100644
--- a/toolchain/diagnostics/coverage_test.cpp
+++ b/toolchain/diagnostics/coverage_test.cpp
@@ -36,10 +36,12 @@ constexpr Kind UntestedKinds[] = {
     Kind::BuildPreludeManifestError,
     Kind::BuildTempDirectoryCreationError,
     Kind::BuildTempDirectoryDeletionError,
+    Kind::CompileCoreManifestError,
     Kind::CompilePreludeManifestError,
     Kind::ConfigFailedToReadDigest,
     Kind::ConfigFailedToSetupTarget,
     Kind::DriverInstallInvalid,
+    Kind::LinkCarbonPreludeBuildFailed,
 
     // These diagnose filesystem issues that are hard to unit test.
     Kind::ErrorReadingFile,
diff --git a/toolchain/diagnostics/kind.def b/toolchain/diagnostics/kind.def
index 7c2e68569b13..345bc06a6ad6 100644
--- a/toolchain/diagnostics/kind.def
+++ b/toolchain/diagnostics/kind.def
@@ -30,6 +30,7 @@ CARBON_DIAGNOSTIC_KIND(BuildOutputFileOpenError)
 CARBON_DIAGNOSTIC_KIND(BuildPreludeManifestError)
 CARBON_DIAGNOSTIC_KIND(BuildTempDirectoryCreationError)
 CARBON_DIAGNOSTIC_KIND(BuildTempDirectoryDeletionError)
+CARBON_DIAGNOSTIC_KIND(CompileCoreManifestError)
 CARBON_DIAGNOSTIC_KIND(CompilePhaseFlagConflict)
 CARBON_DIAGNOSTIC_KIND(CompilePreludeManifestError)
 CARBON_DIAGNOSTIC_KIND(CompileInputNotRegularFile)
@@ -42,6 +43,7 @@ CARBON_DIAGNOSTIC_KIND(FailureBuildingRuntimes)
 CARBON_DIAGNOSTIC_KIND(FailureRunningClang)
 CARBON_DIAGNOSTIC_KIND(FailureRunningClangToLink)
 CARBON_DIAGNOSTIC_KIND(FormatMultipleFilesToOneOutput)
+CARBON_DIAGNOSTIC_KIND(LinkCarbonPreludeBuildFailed)
 CARBON_DIAGNOSTIC_KIND(LinkObjectFilesMissing)
 CARBON_DIAGNOSTIC_KIND(LinkOutputOptionMissing)
 CARBON_DIAGNOSTIC_KIND(ToolFuzzingDisallowed)
diff --git a/toolchain/driver/BUILD b/toolchain/driver/BUILD
index 663e71a6fc18..911c1b4249f3 100644
--- a/toolchain/driver/BUILD
+++ b/toolchain/driver/BUILD
@@ -184,6 +184,8 @@ cc_library(
         "build_runtimes_subcommand.h",
         "build_subcommand.cpp",
         "build_subcommand.h",
+        "carbon_runtimes.cpp",
+        "carbon_runtimes.h",
         "clang_subcommand.cpp",
         "clang_subcommand.h",
         "compile_subcommand.cpp",
@@ -235,6 +237,7 @@ cc_library(
         "//toolchain/base:clang_invocation",
         "//toolchain/base:install_paths",
         "//toolchain/base:llvm_tools",
+        "//toolchain/base:runtimes_build_info",
         "//toolchain/base:shared_value_stores",
         "//toolchain/base:timings",
         "//toolchain/check",
diff --git a/toolchain/driver/build_runtimes_subcommand.cpp b/toolchain/driver/build_runtimes_subcommand.cpp
index 88bef6e13594..a1f133ad4d1e 100644
--- a/toolchain/driver/build_runtimes_subcommand.cpp
+++ b/toolchain/driver/build_runtimes_subcommand.cpp
@@ -5,6 +5,7 @@
 #include "toolchain/driver/build_runtimes_subcommand.h"
 
 #include "llvm/TargetParser/Triple.h"
+#include "toolchain/driver/carbon_runtimes.h"
 #include "toolchain/driver/clang_runner.h"
 #include "toolchain/driver/clang_runtimes.h"
 
@@ -97,6 +98,7 @@ auto BuildRuntimesSubcommand::RunInternal(DriverEnv& driver_env)
     CARBON_RETURN_IF_ERROR(runtimes.Remove(Runtimes::ClangResourceDir));
     CARBON_RETURN_IF_ERROR(runtimes.Remove(Runtimes::LibUnwind));
     CARBON_RETURN_IF_ERROR(runtimes.Remove(Runtimes::Libcxx));
+    CARBON_RETURN_IF_ERROR(runtimes.Remove(Runtimes::CarbonCore));
   }
 
   ClangResourceDirBuilder resource_dir_builder(&runner, driver_env.thread_pool,
@@ -108,10 +110,13 @@ auto BuildRuntimesSubcommand::RunInternal(DriverEnv& driver_env)
   ClangArchiveRuntimesBuilder<Runtimes::Libcxx> libcxx_builder(
       &runner, driver_env.thread_pool, llvm::Triple(features.target),
       &runtimes);
+  CarbonPreludeBuilder prelude_builder(&driver_env, &runtimes,
+                                       &options_.codegen_options);
 
   CARBON_RETURN_IF_ERROR(std::move(resource_dir_builder).Wait());
   CARBON_RETURN_IF_ERROR(std::move(lib_unwind_builder).Wait());
   CARBON_RETURN_IF_ERROR(std::move(libcxx_builder).Wait());
+  CARBON_RETURN_IF_ERROR(std::move(prelude_builder).Build());
 
   return runtimes.base_path();
 }
diff --git a/toolchain/driver/build_subcommand.cpp b/toolchain/driver/build_subcommand.cpp
index e38a3dee1d7e..94e3cc41d9df 100644
--- a/toolchain/driver/build_subcommand.cpp
+++ b/toolchain/driver/build_subcommand.cpp
@@ -15,8 +15,8 @@
 namespace Carbon {
 
 auto BuildSubcommandOptions::Build(CommandLine::CommandBuilder& b) -> void {
-  compile_options.BuildForBuildSubcommand(b);
-  link_options.BuildForBuildSubcommand(b);
+  compile_options.BuildForBuildSubcommand(b, &codegen_options);
+  link_options.BuildForBuildSubcommand(b, &codegen_options);
 
   b.AddFlag(
       {
@@ -50,6 +50,8 @@ auto BuildSubcommand::BuildOptions(CommandLine::CommandBuilder& b) -> void {
 }
 
 auto BuildSubcommand::Run(DriverEnv& driver_env) -> DriverResult {
+  options_.compile_options.FixupFlags();
+
   if (driver_env.fuzzing && !options_.compile_options.clang_args.empty()) {
     // Parsing specific Clang arguments can reach deep into
     // external libraries that aren't fuzz clean.
@@ -72,7 +74,7 @@ auto BuildSubcommand::Run(DriverEnv& driver_env) -> DriverResult {
     }
   }
 
-  auto on_exit = llvm::scope_exit([&]() {
+  auto on_exit = llvm::scope_exit([&] {
     // Clean up the temporary directory created for compile results.
     if (temp_dir) {
       auto remove_result = std::move(*temp_dir).Remove();
diff --git a/toolchain/driver/build_subcommand.h b/toolchain/driver/build_subcommand.h
index 8a764e939427..51832d513398 100644
--- a/toolchain/driver/build_subcommand.h
+++ b/toolchain/driver/build_subcommand.h
@@ -6,6 +6,7 @@
 #define CARBON_TOOLCHAIN_DRIVER_BUILD_SUBCOMMAND_H_
 
 #include "common/command_line.h"
+#include "toolchain/driver/codegen_options.h"
 #include "toolchain/driver/compile_options.h"
 #include "toolchain/driver/driver_env.h"
 #include "toolchain/driver/driver_subcommand.h"
@@ -17,6 +18,7 @@ namespace Carbon {
 struct BuildSubcommandOptions {
   auto Build(CommandLine::CommandBuilder& b) -> void;
 
+  CodegenOptions codegen_options;
   CompileOptions compile_options;
   LinkOptions link_options;
   bool use_temp_dir;
diff --git a/toolchain/driver/carbon_runtimes.cpp b/toolchain/driver/carbon_runtimes.cpp
new file mode 100644
index 000000000000..c03613c8afbd
--- /dev/null
+++ b/toolchain/driver/carbon_runtimes.cpp
@@ -0,0 +1,108 @@
+// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
+// Exceptions. See /LICENSE for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+#include "toolchain/driver/carbon_runtimes.h"
+
+#include "toolchain/base/install_paths.h"
+#include "toolchain/base/runtimes_build_info.h"
+
+namespace Carbon {
+
+CarbonRuntimesBuilderBase::CarbonRuntimesBuilderBase(
+    DriverEnv* driver_env, const CodegenOptions* codegen_options)
+    : compile_options_(codegen_options),
+      compile_driver_(&compile_options_),
+      driver_env_(driver_env),
+      install_root_(driver_env->installation->root()),
+      result_(Error("Did not finish building the Carbon runtimes!")) {
+  // Each prelude file explicitly imports the other parts of the prelude it
+  // needs.
+  compile_options_.prelude_import = false;
+  // Don't also try and compile the rest of the core when compiling the prelude.
+  compile_options_.include_carbon_core = false;
+}
+
+CarbonPreludeBuilder::CarbonPreludeBuilder(
+    DriverEnv* driver_env, Runtimes* runtimes,
+    const CodegenOptions* codegen_options)
+    : CarbonRuntimesBuilderBase(driver_env, codegen_options) {
+  auto build_dir_or_error = runtimes->Build(Runtimes::CarbonCore);
+  if (!build_dir_or_error.ok()) {
+    result_ = std::move(build_dir_or_error).error();
+    return;
+  }
+  auto build_dir = *std::move(build_dir_or_error);
+  if (std::holds_alternative<std::filesystem::path>(build_dir)) {
+    // Reuse cached build.
+    result_ = std::get<std::filesystem::path>(std::move(build_dir));
+    return;
+  }
+
+  runtimes_builder_ = std::get<Runtimes::Builder>(std::move(build_dir));
+  lib_path_ = std::filesystem::path("lib/core") /
+              compile_options_.codegen_options->target.str();
+}
+
+auto CarbonPreludeBuilder::Build() && -> ErrorOr<std::filesystem::path> {
+  // If we didn't make a Builder in the constructor we either encountered an
+  // error or an already cached build, return the result.
+  if (!runtimes_builder_) {
+    return std::move(result_);
+  }
+
+  // Create the output directory.
+  auto lib_dir_result = runtimes_builder_->dir().CreateDirectories(lib_path_);
+  if (!lib_dir_result.ok()) {
+    return std::move(lib_dir_result).error();
+  }
+  auto lib_dir = *std::move(lib_dir_result);
+
+  // Gather the absolute paths to the prelude source files into a string list.
+  // This serves as a backing store for the `llvm::StringRef` inputs required to
+  // the `CompileDriver` via `compile_options_`.
+  llvm::SmallVector<std::string> prelude_source_files;
+  llvm::for_each(RuntimesBuildInfo::CarbonCorePreludeSrcs,
+                 [&](llvm::StringRef src) -> void {
+                   prelude_source_files.emplace_back(
+                       (install_root_ / std::filesystem::path(src.str())));
+                   compile_options_.input_filenames.emplace_back(
+                       llvm::StringRef(prelude_source_files.back()));
+                 });
+
+  auto install_root_length = install_root_.string().length();
+  CARBON_CHECK(
+      compile_driver_.Initialize(
+          *driver_env_,
+          [&](llvm::StringRef input_filename) -> std::string {
+            // Make the input path relative to the install_root_ again, and
+            // replace the `.carbon` extension with a `.o`.
+            auto object_path =
+                std::filesystem::path(
+                    input_filename.substr(install_root_length).str())
+                    .replace_extension(".o");
+            auto output_path =
+                runtimes_builder_->path() / lib_path_ / object_path;
+            // The output path may contain subdirectories that haven't yet been
+            // created, so check for that and create if necessary.
+            if (!std::filesystem::exists(output_path.parent_path())) {
+              CARBON_CHECK(
+                  runtimes_builder_->dir()
+                      .CreateDirectories(lib_path_ / output_path.parent_path())
+                      .ok(),
+                  "Failed to make output subdirectory while building Carbon "
+                  "prelude.");
+            }
+            llvm::errs() << "mapping: `" << input_filename << "` to: `"
+                         << output_path << "`\n";
+            return output_path.string();
+          }),
+      "Failed to initialize compiler driver for Carbon prelude.");
+  CARBON_CHECK(compile_driver_.Compile(*driver_env_).success,
+               "Failed to compile Carbon prelude.");
+
+  result_ = (*std::move(runtimes_builder_)).Commit();
+  return std::move(result_);
+}
+
+}  // namespace Carbon
diff --git a/toolchain/driver/carbon_runtimes.h b/toolchain/driver/carbon_runtimes.h
new file mode 100644
index 000000000000..e6bfbbf09c03
--- /dev/null
+++ b/toolchain/driver/carbon_runtimes.h
@@ -0,0 +1,65 @@
+// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
+// Exceptions. See /LICENSE for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+#ifndef CARBON_TOOLCHAIN_DRIVER_CARBON_RUNTIMES_H_
+#define CARBON_TOOLCHAIN_DRIVER_CARBON_RUNTIMES_H_
+
+#include <filesystem>
+#include <memory>
+
+#include "common/error.h"
+#include "llvm/ADT/ArrayRef.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/Support/ThreadPool.h"
+#include "llvm/TargetParser/Triple.h"
+#include "toolchain/driver/codegen_options.h"
+#include "toolchain/driver/compile_driver.h"
+#include "toolchain/driver/compile_options.h"
+#include "toolchain/driver/driver_env.h"
+#include "toolchain/driver/runtimes_cache.h"
+
+namespace Carbon {
+
+struct CompileOptions;
+
+// Common code for Carbon runtimes builders.
+//
+// Although this class has only a single derivation for building the prelude,
+// we anticipate wanting to build other parts of Core in the future and so
+// design for extensibility.
+// TODO: Build all parts of the Core, not just the prelude.
+class CarbonRuntimesBuilderBase {
+ protected:
+  CarbonRuntimesBuilderBase(DriverEnv* driver_env,
+                            const CodegenOptions* codegen_options);
+
+  // We use protected members as this base is just factoring out common
+  // implementation details of other runners.
+  //
+  // NOLINTBEGIN(misc-non-private-member-variables-in-classes)
+  //
+  CompileOptions compile_options_;
+  CompileDriver compile_driver_;
+  DriverEnv* driver_env_;
+  // Base path for the input source files. The enumerated constant list of
+  // paths is all relative to this base path.
+  std::filesystem::path install_root_;
+  // Output subpath for the built binaries.
+  std::filesystem::path lib_path_;
+  ErrorOr<std::filesystem::path> result_;
+  std::optional<Runtimes::Builder> runtimes_builder_;
+  // NOLINTEND(misc-non-private-member-variables-in-classes)
+};
+
+class CarbonPreludeBuilder : public CarbonRuntimesBuilderBase {
+ public:
+  CarbonPreludeBuilder(DriverEnv* driver_env, Runtimes* runtimes,
+                       const CodegenOptions* codegen_options);
+  auto Build() && -> ErrorOr<std::filesystem::path>;
+};
+
+}  // namespace Carbon
+
+#endif  // CARBON_TOOLCHAIN_DRIVER_CARBON_RUNTIMES_H_
diff --git a/toolchain/driver/clang_runtimes.h b/toolchain/driver/clang_runtimes.h
index 37ca51db2001..8d8f53ebd9cc 100644
--- a/toolchain/driver/clang_runtimes.h
+++ b/toolchain/driver/clang_runtimes.h
@@ -105,8 +105,7 @@ class ClangRuntimesBuilderBase::ArchiveBuilder {
   //
   // - The `builder` must outlive this object.
   // - `archive_path` is the _relative_ path of the archive file within the
-  // built
-  //   runtimes directory.
+  //   built runtimes directory.
   // - `src_files` is a list of the _absolute_ file paths to build into the
   //   archive.
   // - `cflags` are the compile flags that should be used for all the compiles
diff --git a/toolchain/driver/compile_driver.cpp b/toolchain/driver/compile_driver.cpp
index 929823c9af2e..26afb1be7494 100644
--- a/toolchain/driver/compile_driver.cpp
+++ b/toolchain/driver/compile_driver.cpp
@@ -481,9 +481,27 @@ auto CompileDriver::Initialize(
     }
   }
 
+  // Append the Core library files on request.
+  llvm::SmallVector<std::string> core_library;
+  if (options_->include_carbon_core && !options_->custom_core &&
+      options_->phase >= CompileOptions::Phase::Check) {
+    if (auto find = driver_env.installation->ReadCarbonCoreManifest();
+        !find.ok()) {
+      CARBON_DIAGNOSTIC(CompileCoreManifestError, Error, "{0}", std::string);
+      driver_env.emitter.Emit(CompileCoreManifestError,
+                              PrintToString(find.error()));
+      return false;
+    } else {
+      // Note we also compile any .impl files, as we will need to include them
+      // in the subsequent link step.
+      core_library = std::move(*find);
+    }
+  }
+
   // Prepare CompilationUnits before building scope exit handlers.
   int unit_index = -1;
-  int total_unit_count = prelude.size() + options_->input_filenames.size();
+  int total_unit_count =
+      prelude.size() + core_library.size() + options_->input_filenames.size();
   auto unit_builder = [&](llvm::StringRef filename) {
     ++unit_index;
     return std::make_unique<CompilationUnit>(
@@ -491,6 +509,7 @@ auto CompileDriver::Initialize(
         driver_env.consumer, filename, map_input(filename), target);
   };
   llvm::append_range(units_, llvm::map_range(prelude, unit_builder));
+  llvm::append_range(units_, llvm::map_range(core_library, unit_builder));
   input_filenames_index_ = units_.size();
   llvm::append_range(units_,
                      llvm::map_range(options_->input_filenames, unit_builder));
diff --git a/toolchain/driver/compile_driver.h b/toolchain/driver/compile_driver.h
index f7774c2796d2..35b3ee08a868 100644
--- a/toolchain/driver/compile_driver.h
+++ b/toolchain/driver/compile_driver.h
@@ -238,13 +238,13 @@ class CompileDriver {
   // The `map_input` function maps an input file name to an output static
   // object name.
   // Returns `false` on configuration error.
-  auto Initialize(
+  [[nodiscard]] auto Initialize(
       DriverEnv& driver_env,
       llvm::function_ref<auto(llvm::StringRef)->std::string> map_input) -> bool;
 
   // Performs the compilation process on each input specified in the
   // `CompileOptions` provided at construction time.
-  auto Compile(DriverEnv& driver_env) -> DriverResult;
+  [[nodiscard]] auto Compile(DriverEnv& driver_env) -> DriverResult;
 
   // Returns the index in the `units()` array of the first input file
   // specified by the user on the command line. This may not be the first
diff --git a/toolchain/driver/compile_options.cpp b/toolchain/driver/compile_options.cpp
index 7f143854e662..9783164a326a 100644
--- a/toolchain/driver/compile_options.cpp
+++ b/toolchain/driver/compile_options.cpp
@@ -14,8 +14,8 @@ namespace {
 
 // Provides command-line options common to both `compile` and `link`
 // subcommands.
-auto BuildSharedOptions(CommandLine::CommandBuilder& b, CompileOptions* options)
-    -> void {
+auto BuildSharedOptions(CommandLine::CommandBuilder& b, CompileOptions* options,
+                        CodegenOptions* cg_options) -> void {
   b.AddStringPositionalArg(
       {
           .name = "FILE",
@@ -82,7 +82,8 @@ Selects the amount of optimization to perform.
   // Include the common code generation options at this point to render it
   // after the more common options above, but before the more unusual options
   // below.
-  options->codegen_options->Build(b);
+  cg_options->Build(b);
+  options->codegen_options = cg_options;
 
   b.AddFlag(
       {
@@ -121,9 +122,10 @@ Whether to use the implicit prelude import. Enabled by default.
 
 }  // namespace
 
-auto CompileOptions::BuildForCompileSubcommand(CommandLine::CommandBuilder& b)
+auto CompileOptions::BuildForCompileSubcommand(CommandLine::CommandBuilder& b,
+                                               CodegenOptions* cg_options)
     -> void {
-  BuildSharedOptions(b, this);
+  BuildSharedOptions(b, this, cg_options);
 
   b.AddOneOfOption(
       {
@@ -386,11 +388,34 @@ Use the string form of the fingerprint from mangling instead of the hash form.
 )""",
       },
       [&](auto& arg_b) { arg_b.Set(&mangle_string_fingerprint); });
+  b.AddFlag(
+      {
+          .name = "include-carbon-core",
+          .help = R"""(
+Automatically include the Core libraries files in the compilation.
+
+Note this refers to the Core libraries files other than the prelude, the
+inclusion of which is currently controlled by the `prelude_import` flag. If
+the `prelude_import` flag is set to false, this is also silently set to false.
+)""",
+      },
+      [&](auto& arg_b) {
+        arg_b.Default(true);
+        arg_b.Set(&include_carbon_core);
+      });
 }
 
-auto CompileOptions::BuildForBuildSubcommand(CommandLine::CommandBuilder& b)
+auto CompileOptions::BuildForBuildSubcommand(CommandLine::CommandBuilder& b,
+                                             CodegenOptions* cg_options)
     -> void {
-  BuildSharedOptions(b, this);
+  include_carbon_core = true;
+  BuildSharedOptions(b, this, cg_options);
+}
+
+auto CompileOptions::FixupFlags() -> void {
+  if (!prelude_import) {
+    include_carbon_core = false;
+  }
 }
 
 auto CompileOptions::ValidatePhase(Diagnostics::NoLocEmitter& emitter) const
diff --git a/toolchain/driver/compile_options.h b/toolchain/driver/compile_options.h
index a36a8223089d..bf78e6333d8c 100644
--- a/toolchain/driver/compile_options.h
+++ b/toolchain/driver/compile_options.h
@@ -5,8 +5,6 @@
 #ifndef CARBON_TOOLCHAIN_DRIVER_COMPILE_OPTIONS_H_
 #define CARBON_TOOLCHAIN_DRIVER_COMPILE_OPTIONS_H_
 
-#include <memory>
-
 #include "common/command_line.h"
 #include "common/error.h"
 #include "common/ostream.h"
@@ -31,6 +29,10 @@ namespace Carbon {
 //
 // Members are documented in their respective `Build` functions.
 struct CompileOptions {
+  CompileOptions() = default;
+  explicit CompileOptions(const CodegenOptions* cg_options)
+      : codegen_options(cg_options) {}
+
   enum class Phase : int8_t {
     Lex,
     Parse,
@@ -43,8 +45,20 @@ struct CompileOptions {
   friend auto operator<<(llvm::raw_ostream& out, Phase phase)
       -> llvm::raw_ostream&;
 
-  auto BuildForCompileSubcommand(CommandLine::CommandBuilder& b) -> void;
-  auto BuildForBuildSubcommand(CommandLine::CommandBuilder& b) -> void;
+  // Will use the provided `cg_options` to initialize the `codegen_options`
+  // member variable. This is provided separately so we can call `Build()`
+  // at a specific time in the initialization sequence for the correct priority
+  // of the Codegen Options build flags and help documentation.
+  auto BuildForCompileSubcommand(CommandLine::CommandBuilder& b,
+                                 CodegenOptions* cg_options) -> void;
+  auto BuildForBuildSubcommand(CommandLine::CommandBuilder& b,
+                               CodegenOptions* cg_options) -> void;
+
+  // It's possible to specify flags that will break the compile. In particular
+  // specifying `--no-prelude-import` and `--include-carbon-core` will cause
+  // the Core compilation to fail. This function quietly disables Carbon Core
+  // inclusion if the prelude import is disabled.
+  auto FixupFlags() -> void;
 
   // Validate that the compile options make sense for the compilation phase
   // selected.
@@ -66,8 +80,10 @@ struct CompileOptions {
       -> ErrorOr<std::shared_ptr<clang::CompilerInvocation>>;
 
   Lower::OptimizationLevel opt_level = Lower::OptimizationLevel::Debug;
-  std::shared_ptr<CodegenOptions> codegen_options =
-      std::make_shared<CodegenOptions>();
+
+  // This pointer is set by `Build*()` functions, in other use cases this
+  // pointer will need to be set manually.
+  const CodegenOptions* codegen_options = nullptr;
 
   llvm::SmallVector<llvm::StringRef> input_filenames;
   llvm::SmallVector<llvm::StringRef> clang_args;
@@ -97,8 +113,9 @@ struct CompileOptions {
   bool stream_errors = false;
   bool preorder_parse_tree = false;
   bool builtin_sem_ir = false;
-  bool prelude_import = false;
+  bool prelude_import = true;
   bool output_last_input_only = false;
+  bool include_carbon_core = true;
 
   llvm::SmallVector<llvm::StringRef> exclude_dump_file_prefixes;
 
diff --git a/toolchain/driver/compile_subcommand.cpp b/toolchain/driver/compile_subcommand.cpp
index 7a8fd6b96806..f2c65ebcc166 100644
--- a/toolchain/driver/compile_subcommand.cpp
+++ b/toolchain/driver/compile_subcommand.cpp
@@ -26,19 +26,21 @@ can be written to standard output as these phases progress.
 CompileSubcommand::CompileSubcommand() : DriverSubcommand(SubcommandInfo) {}
 
 auto CompileSubcommand::Run(DriverEnv& driver_env) -> DriverResult {
-  if (driver_env.fuzzing && !options_.clang_args.empty()) {
+  options_.compile_options.FixupFlags();
+
+  if (driver_env.fuzzing && !options_.compile_options.clang_args.empty()) {
     // Parsing specific Clang arguments can reach deep into
     // external libraries that aren't fuzz clean.
     TestAndDiagnoseIfFuzzingExternalLibraries(driver_env, "compile");
     return {.success = false};
   }
 
-  auto compile_driver = CompileDriver(&options_);
+  auto compile_driver = CompileDriver(&options_.compile_options);
 
-  if (!compile_driver.Initialize(driver_env,
-                                 [&](llvm::StringRef) -> std::string {
-                                   return options_.output_filename.str();
-                                 })) {
+  if (!compile_driver.Initialize(
+          driver_env, [&](llvm::StringRef) -> std::string {
+            return options_.compile_options.output_filename.str();
+          })) {
     return {.success = false};
   }
 
diff --git a/toolchain/driver/compile_subcommand.h b/toolchain/driver/compile_subcommand.h
index 50f1260bbd9a..47a64ba13353 100644
--- a/toolchain/driver/compile_subcommand.h
+++ b/toolchain/driver/compile_subcommand.h
@@ -12,19 +12,29 @@
 
 namespace Carbon {
 
+// Options for the compile subcommand.
+struct CompileSubcommandOptions {
+  auto Build(CommandLine::CommandBuilder& b) -> void {
+    compile_options.BuildForCompileSubcommand(b, &codegen_options);
+  }
+
+  CodegenOptions codegen_options;
+  CompileOptions compile_options;
+};
+
 // Implements the compile subcommand of the driver.
 class CompileSubcommand : public DriverSubcommand {
  public:
   explicit CompileSubcommand();
 
   auto BuildOptions(CommandLine::CommandBuilder& b) -> void override {
-    options_.BuildForCompileSubcommand(b);
+    options_.Build(b);
   }
 
   auto Run(DriverEnv& driver_env) -> DriverResult override;
 
  private:
-  CompileOptions options_;
+  CompileSubcommandOptions options_;
 };
 
 }  // namespace Carbon
diff --git a/toolchain/driver/link_driver.cpp b/toolchain/driver/link_driver.cpp
index 97cb1f027020..fd4cd2d24cdd 100644
--- a/toolchain/driver/link_driver.cpp
+++ b/toolchain/driver/link_driver.cpp
@@ -4,10 +4,57 @@
 
 #include "toolchain/driver/link_driver.h"
 
+#include "common/filesystem.h"
+#include "toolchain/base/runtimes_build_info.h"
+#include "toolchain/driver/carbon_runtimes.h"
+
 namespace Carbon {
 
 LinkDriver::LinkDriver(LinkOptions* options) : options_(options) {}
 
+namespace {
+
+auto object_search(Filesystem::DirRef base_dir, std::filesystem::path base_path,
+                   llvm::SmallVector<std::string>& prelude_paths) -> void {
+  llvm::SmallVector<std::filesystem::path> work_paths({"."});
+  while (!work_paths.empty()) {
+    auto relative_path = work_paths.back();
+    work_paths.pop_back();
+    auto relative_dir = base_dir.OpenDir(relative_path);
+    CARBON_CHECK(relative_dir.ok());
+    llvm::SmallVector<std::filesystem::path> relative_sub_paths;
+    llvm::SmallVector<std::filesystem::path> relative_file_paths;
+    CARBON_CHECK(
+        relative_dir
+            ->AppendEntriesIf(relative_sub_paths, relative_file_paths,
+                              [&relative_dir](llvm::StringRef name) -> bool {
+                                auto path = std::filesystem::path(name.str());
+                                auto stat = relative_dir->Stat(path);
+                                CARBON_CHECK(stat.ok());
+                                if (stat->is_dir()) {
+                                  return true;
+                                }
+                                return path.extension() == ".o";
+                              })
+            .ok());
+    llvm::append_range(
+        work_paths,
+        llvm::map_range(relative_sub_paths,
+                        [relative_path](std::filesystem::path sub_path) {
+                          return relative_path / sub_path;
+                        }));
+    llvm::append_range(
+        prelude_paths,
+        llvm::map_range(
+            relative_file_paths,
+            [relative_path, base_path](std::filesystem::path file_path) {
+              return (base_path / relative_path / file_path).string();
+            }));
+  }
+}
+
+}  // namespace
+
 auto LinkDriver::Link(DriverEnv& driver_env) -> DriverResult {
   // TODO: Currently we use the Clang driver to link. This works well on Unix
   // OSes but we likely need to directly build logic to invoke `link.exe` on
@@ -45,6 +92,51 @@ auto LinkDriver::Link(DriverEnv& driver_env) -> DriverResult {
     return {.success = false};
   }
 
+  // Find or build the Carbon Core runtimes for linking the prelude into the
+  // binary.
+  bool include_prelude = false;
+  std::filesystem::path core_path;
+  Filesystem::DirRef runtimes_dir;
+  std::filesystem::path runtimes_path;
+  std::optional<Runtimes> runtimes_cache;
+  if (options_->link_prelude_files) {
+    if (driver_env.prebuilt_runtimes) {
+      auto error_or_path =
+          driver_env.prebuilt_runtimes->Get(Runtimes::CarbonCore);
+      CARBON_CHECK(error_or_path.ok(),
+                   "Prebuilt runtimes failed to fetch for Carbon prelude: {}",
+                   error_or_path.error().message());
+      core_path = std::move(*error_or_path);
+      runtimes_dir = driver_env.prebuilt_runtimes->base_dir();
+      runtimes_path = driver_env.prebuilt_runtimes->base_path();
+      include_prelude = true;
+    } else if (driver_env.build_runtimes_on_demand) {
+      Runtimes::Cache::Features features = {
+          .target = options_->codegen_options->target.str()};
+      auto runtimes_or_error = driver_env.runtimes_cache.Lookup(features);
+      CARBON_CHECK(runtimes_or_error.ok(), "Runtimes cache lookup failed: {}",
+                   runtimes_or_error.error().message());
+      auto runtimes = std::move(*runtimes_or_error);
+      CarbonPreludeBuilder prelude_builder(&driver_env, &runtimes,
+                                           options_->codegen_options);
+      auto path_or_error = std::move(prelude_builder).Build();
+      if (!path_or_error.ok()) {
+        CARBON_DIAGNOSTIC(LinkCarbonPreludeBuildFailed, Error,
+                          "Failed to build Carbon prelude during linking: {0}",
+                          std::string);
+        driver_env.emitter.Emit(LinkCarbonPreludeBuildFailed,
+                                path_or_error.error().message());
+        return {.success = false};
+      }
+      core_path = std::move(*path_or_error);
+      runtimes_dir = runtimes.base_dir();
+      runtimes_path = runtimes.base_path();
+      // Keep the Runtimes object in scope so we can use it during linking.
+      runtimes_cache = std::move(runtimes);
+      include_prelude = true;
+    }
+  }
+
   // Note that we append any extra Clang args before our object filenames. This
   // allows us to propagate object filenames that collide with Clang flags using
   // `--` before the filenames. While in theory, this could create a problem in
@@ -53,6 +145,29 @@ auto LinkDriver::Link(DriverEnv& driver_env) -> DriverResult {
   clang_args.append(options_->extra_clang_args.begin(),
                     options_->extra_clang_args.end());
   clang_args.push_back("--");
+
+  // Append the Carbon prelude object files to the link.
+  // TODO: should also be able to link in the rest of the Core object files,
+  // if needed.
+  llvm::SmallVector<std::string> prelude_paths;
+  if (include_prelude) {
+    // Open subdirectory specifically for the object files relative to the
+    // runtimes base path.
+    auto relative_path = core_path.lexically_relative(runtimes_path);
+    auto core_dir_or_error = runtimes_dir.OpenDir(relative_path);
+    CARBON_CHECK(core_dir_or_error.ok(),
+                 "Failed to open prelude binaries directory at {}, error: {}",
+                 runtimes_path / relative_path, core_dir_or_error.error());
+    auto core_dir = std::move(*core_dir_or_error);
+    object_search(core_dir, core_path, prelude_paths);
+    CARBON_CHECK(!prelude_paths.empty(), "Found no prelude files at {}",
+                 runtimes_path / relative_path);
+    llvm::append_range(
+        clang_args, llvm::map_range(prelude_paths, [](const std::string& path) {
+          return llvm::StringRef(path);
+        }));
+  }
+
   clang_args.append(options_->object_filenames.begin(),
                     options_->object_filenames.end());
 
diff --git a/toolchain/driver/link_options.cpp b/toolchain/driver/link_options.cpp
index 49265b12880d..6d9af0100990 100644
--- a/toolchain/driver/link_options.cpp
+++ b/toolchain/driver/link_options.cpp
@@ -27,8 +27,8 @@ system mixes object files and linker flags.
 
 }  // namespace
 
-auto LinkOptions::BuildForLinkSubcommand(CommandLine::CommandBuilder& b)
-    -> void {
+auto LinkOptions::BuildForLinkSubcommand(CommandLine::CommandBuilder& b,
+                                         CodegenOptions* cg_options) -> void {
   b.AddStringPositionalArg(
       {
           .name = "OBJECT_FILE",
@@ -56,14 +56,27 @@ legacy parsing logic.
       },
       [&](auto& arg_b) { arg_b.Set(&output_filename); });
 
-  BuildSharedOptions(b, this);
+  b.AddFlag(
+      {
+          .name = "link_prelude_files",
+          .help = R"""(
+Automatically include the Carbon prelude files in the link.
+)""",
+      },
+      [&](auto& arg_b) {
+        arg_b.Default(true);
+        arg_b.Set(&link_prelude_files);
+      });
 
-  codegen_options = std::make_shared<CodegenOptions>();
-  codegen_options->Build(b);
+  BuildSharedOptions(b, this);
+  cg_options->Build(b);
+  codegen_options = cg_options;
 }
 
-auto LinkOptions::BuildForBuildSubcommand(CommandLine::CommandBuilder& b)
-    -> void {
+auto LinkOptions::BuildForBuildSubcommand(CommandLine::CommandBuilder& b,
+                                          CodegenOptions* cg_options) -> void {
+  codegen_options = cg_options;
+
   b.AddStringOption(
       {
           .name = "output",
@@ -77,6 +90,9 @@ name of the first provided input file.
       [&](auto& arg_b) { arg_b.Set(&output_filename); });
 
   BuildSharedOptions(b, this);
+  // The prelude files have already been built and are part of the input binary
+  // set, so will already be linked through that path.
+  link_prelude_files = false;
 }
 
 }  // namespace Carbon
diff --git a/toolchain/driver/link_options.h b/toolchain/driver/link_options.h
index 0c442fce618e..564bc9e79b80 100644
--- a/toolchain/driver/link_options.h
+++ b/toolchain/driver/link_options.h
@@ -5,8 +5,6 @@
 #ifndef CARBON_TOOLCHAIN_DRIVER_LINK_OPTIONS_H_
 #define CARBON_TOOLCHAIN_DRIVER_LINK_OPTIONS_H_
 
-#include <memory>
-
 #include "common/command_line.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/StringRef.h"
@@ -20,11 +18,14 @@ namespace Carbon {
 //
 // See the implementation of `link` for documentation on members.
 struct LinkOptions {
-  auto BuildForLinkSubcommand(CommandLine::CommandBuilder& b) -> void;
-  auto BuildForBuildSubcommand(CommandLine::CommandBuilder& b) -> void;
+  auto BuildForLinkSubcommand(CommandLine::CommandBuilder& b,
+                              CodegenOptions* cg_options) -> void;
+  auto BuildForBuildSubcommand(CommandLine::CommandBuilder& b,
+                               CodegenOptions* cg_options) -> void;
 
-  std::shared_ptr<CodegenOptions> codegen_options;
+  const CodegenOptions* codegen_options = nullptr;
   llvm::StringRef output_filename;
+  bool link_prelude_files = true;
   llvm::SmallVector<llvm::StringRef> object_filenames;
 
   llvm::SmallVector<llvm::StringRef> extra_clang_args;
diff --git a/toolchain/driver/link_subcommand.h b/toolchain/driver/link_subcommand.h
index f074998a8e69..d338bc2dae4c 100644
--- a/toolchain/driver/link_subcommand.h
+++ b/toolchain/driver/link_subcommand.h
@@ -21,12 +21,13 @@ class LinkSubcommand : public DriverSubcommand {
   explicit LinkSubcommand();
 
   auto BuildOptions(CommandLine::CommandBuilder& b) -> void override {
-    options_.BuildForLinkSubcommand(b);
+    options_.BuildForLinkSubcommand(b, &codegen_options);
   }
 
   auto Run(DriverEnv& driver_env) -> DriverResult override;
 
  private:
+  CodegenOptions codegen_options;
   LinkOptions options_;
 };
 
diff --git a/toolchain/driver/runtimes_cache.h b/toolchain/driver/runtimes_cache.h
index e33bccc65630..b2710b9ab81e 100644
--- a/toolchain/driver/runtimes_cache.h
+++ b/toolchain/driver/runtimes_cache.h
@@ -36,15 +36,13 @@ namespace Carbon {
 // build of these components into their designated subdirectories, including
 // synchronizing between different threads or processes trying to build the same
 // component.
-//
-// TODO: Add libc++ to the runtimes tree.
-// TODO: Add the Core library to the runtimes tree.
 class Runtimes {
  public:
   class Builder;
   class Cache;
 
   enum Component {
+    CarbonCore,
     ClangResourceDir,
     LibUnwind,
     Libcxx,
@@ -153,6 +151,8 @@ class Runtimes {
   // This uses `std::string_view` to simply using with paths.
   static constexpr auto ComponentPath(Component component) -> std::string_view {
     switch (component) {
+      case CarbonCore:
+        return "core";
       case ClangResourceDir:
         return "clang_resource_dir";
       case LibUnwind:
diff --git a/toolchain/driver/testdata/compile/optimize/optimize_debug.carbon b/toolchain/driver/testdata/compile/optimize/optimize_debug.carbon
index 5f0209a25597..32a9b2ce0712 100644
--- a/toolchain/driver/testdata/compile/optimize/optimize_debug.carbon
+++ b/toolchain/driver/testdata/compile/optimize/optimize_debug.carbon
@@ -2,7 +2,7 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// ARGS: compile --optimize=debug foo.carbon --target=x86_64-unknown-linux-gnu --phase=optimize --dump-llvm-ir --exclude-dump-file-prefix=%{core}
+// ARGS: compile --optimize=debug foo.carbon --target=x86_64-unknown-linux-gnu --phase=optimize --dump-llvm-ir --exclude-dump-file-prefix=%{core} --include-carbon-core
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
diff --git a/toolchain/driver/testdata/compile/optimize/optimize_default.carbon b/toolchain/driver/testdata/compile/optimize/optimize_default.carbon
index 7af27c466e10..70288c9d8971 100644
--- a/toolchain/driver/testdata/compile/optimize/optimize_default.carbon
+++ b/toolchain/driver/testdata/compile/optimize/optimize_default.carbon
@@ -2,7 +2,7 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// ARGS: compile foo.carbon --target=x86_64-unknown-linux-gnu --phase=optimize --dump-llvm-ir --exclude-dump-file-prefix=%{core}
+// ARGS: compile foo.carbon --target=x86_64-unknown-linux-gnu --phase=optimize --dump-llvm-ir --exclude-dump-file-prefix=%{core} --include-carbon-core
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
diff --git a/toolchain/driver/testdata/compile/optimize/optimize_none.carbon b/toolchain/driver/testdata/compile/optimize/optimize_none.carbon
index 1e7f8d1a5020..0e8b5ecbdb58 100644
--- a/toolchain/driver/testdata/compile/optimize/optimize_none.carbon
+++ b/toolchain/driver/testdata/compile/optimize/optimize_none.carbon
@@ -2,7 +2,7 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// ARGS: compile --optimize=none foo.carbon --target=x86_64-unknown-linux-gnu --phase=optimize --dump-llvm-ir --exclude-dump-file-prefix=%{core}
+// ARGS: compile --optimize=none foo.carbon --target=x86_64-unknown-linux-gnu --phase=optimize --dump-llvm-ir --exclude-dump-file-prefix=%{core} --include-carbon-core
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
diff --git a/toolchain/driver/testdata/compile/optimize/optimize_size.carbon b/toolchain/driver/testdata/compile/optimize/optimize_size.carbon
index ccbcb772ee5c..3d7be7a29135 100644
--- a/toolchain/driver/testdata/compile/optimize/optimize_size.carbon
+++ b/toolchain/driver/testdata/compile/optimize/optimize_size.carbon
@@ -2,7 +2,7 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// ARGS: compile --optimize=size foo.carbon --target=x86_64-unknown-linux-gnu --phase=lower --dump-llvm-ir --exclude-dump-file-prefix=%{core}
+// ARGS: compile --optimize=size foo.carbon --target=x86_64-unknown-linux-gnu --phase=lower --dump-llvm-ir --exclude-dump-file-prefix=%{core} --include-carbon-core
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
diff --git a/toolchain/driver/testdata/compile/optimize/optimize_speed.carbon b/toolchain/driver/testdata/compile/optimize/optimize_speed.carbon
index 201fbdcec6bd..b0661757b907 100644
--- a/toolchain/driver/testdata/compile/optimize/optimize_speed.carbon
+++ b/toolchain/driver/testdata/compile/optimize/optimize_speed.carbon
@@ -2,7 +2,7 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// ARGS: compile --optimize=speed foo.carbon --target=x86_64-unknown-linux-gnu --phase=optimize --dump-llvm-ir --exclude-dump-file-prefix=%{core}
+// ARGS: compile --optimize=speed foo.carbon --target=x86_64-unknown-linux-gnu --phase=optimize --dump-llvm-ir --exclude-dump-file-prefix=%{core} --include-carbon-core
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
diff --git a/toolchain/driver/testdata/verbose.carbon b/toolchain/driver/testdata/verbose.carbon
index fec645e48e4e..99600a95a4b9 100644
--- a/toolchain/driver/testdata/verbose.carbon
+++ b/toolchain/driver/testdata/verbose.carbon
@@ -3,7 +3,7 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // INCLUDE-FILE: toolchain/testing/testdata/min_prelude/none.carbon
-// ARGS: -v compile --phase=codegen --target=x86_64-unknown-linux-gnu --output=%t --output-last-input-only %s
+// ARGS: -v compile --phase=codegen --target=x86_64-unknown-linux-gnu --output=%t --no-include-carbon-core --output-last-input-only %s
 //
 // Verifies that various phases are included in vlog output.
 //
diff --git a/toolchain/install/BUILD b/toolchain/install/BUILD
index 0994fa8e85ce..0fe693273d6a 100644
--- a/toolchain/install/BUILD
+++ b/toolchain/install/BUILD
@@ -34,6 +34,7 @@ load(
 load("@llvm-project//libcxx:libcxx_library.bzl", "libcxx_and_abi_copts")
 load("@llvm-project//libunwind:libunwind_library.bzl", "libunwind_copts")
 load("@rules_python//python:defs.bzl", "py_test")
+load("//bazel/carbon_rules:defs.bzl", "carbon_prelude")
 load("//bazel/cc_rules:defs.bzl", "cc_binary", "cc_library", "cc_test")
 load(
     "//bazel/cc_toolchains:carbon_bootstrapping.bzl",
@@ -147,6 +148,12 @@ toolchain_files(
     prefix = "core/",
 )
 
+toolchain_files(
+    name = "core_library",
+    srcs = ["//core:core_library"],
+    prefix = "core/",
+)
+
 toolchain_files(
     name = "clang_builtin_hdrs",
     srcs = ["@llvm-project//clang:builtin_headers_gen"],
@@ -367,6 +374,7 @@ filegroup(
         ":builtins_all_srcs",
         ":clang_hdrs",
         ":core",
+        ":core_library",
         ":install_marker",
         ":installed_bazel_files",
         ":libc_internal_libcxx_hdrs",
@@ -483,6 +491,15 @@ filegroup(
     output_group = "archive",
 )
 
+carbon_prelude(
+    name = "carbon_prelude",
+    srcs = [":core"],
+    target_compatible_with = select({
+        ":is_runtimes_build": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
+)
+
 cc_library(
     name = "libunwind",
     srcs = [":libunwind_srcs"],
@@ -576,6 +593,7 @@ filegroup(
 carbon_runtimes_config(
     name = "runtimes_cfg",
     builtins_archive = ":builtins_archive",
+    carbon_prelude_prebuilt = ":carbon_prelude",
     clang_hdrs_prefix = "llvm/lib/clang/{0}/include/".format(LLVM_VERSION_MAJOR),
     crt_copts = crt_copts + [
         # Disable all sanitizers for CRT objects.
diff --git a/toolchain/install/install_test.py b/toolchain/install/install_test.py
index 38ef265b374d..24aa65510084 100644
--- a/toolchain/install/install_test.py
+++ b/toolchain/install/install_test.py
@@ -135,7 +135,13 @@ class InstallTest(unittest.TestCase):
         try:
             obj_file = self.tmpdir / f"{name}.o"
             subprocess.run(
-                [carbon, "compile", f"--output={obj_file}", src_file],
+                [
+                    carbon,
+                    "compile",
+                    "--no-include-carbon-core",
+                    f"--output={obj_file}",
+                    src_file,
+                ],
                 check=True,
                 capture_output=True,
                 text=True,
diff --git a/toolchain/language_server/BUILD b/toolchain/language_server/BUILD
index 6c675a1a47a6..c1ad6f92d726 100644
--- a/toolchain/language_server/BUILD
+++ b/toolchain/language_server/BUILD
@@ -41,6 +41,7 @@ cc_library(
         "//toolchain/check",
         "//toolchain/diagnostics:emitter",
         "//toolchain/diagnostics:file_diagnostics",
+        "//toolchain/driver:codegen_options",
         "//toolchain/driver:compile_driver",
         "//toolchain/lex",
         "//toolchain/lex:tokenized_buffer",
diff --git a/toolchain/language_server/context.cpp b/toolchain/language_server/context.cpp
index df58a4ba49ba..28d26f85800b 100644
--- a/toolchain/language_server/context.cpp
+++ b/toolchain/language_server/context.cpp
@@ -228,11 +228,13 @@ auto Context::File::SetText(Context& context, std::optional<int64_t> version,
   driver_env.vlog_stream =
       static_cast<llvm::raw_pwrite_stream*>(context.vlog_stream());
 
-  options_ = CompileOptions();
-  options_.codegen_options->target = options_.codegen_options->host;
+  codegen_options_ = CodegenOptions();
+  options_ = CompileOptions(&codegen_options_);
+  codegen_options_.target = codegen_options_.host;
   options_.phase = CompileOptions::Phase::Check;
   options_.prelude_import = context.prelude_import();
   options_.input_filenames.push_back(filename());
+  options_.FixupFlags();
 
   compile_driver_ = std::make_unique<CompileDriver>(&options_);
   auto map_input = [](llvm::StringRef) -> std::string { return ""; };
@@ -240,7 +242,10 @@ auto Context::File::SetText(Context& context, std::optional<int64_t> version,
     context.PublishDiagnostics(consumer.params());
     return;
   }
-  compile_driver_->Compile(driver_env);
+  if (!compile_driver_->Compile(driver_env).success) {
+    context.PublishDiagnostics(consumer.params());
+    return;
+  }
 
   // Note we need to publish diagnostics even when empty.
   // TODO: Consider caching previously published diagnostics and only publishing
diff --git a/toolchain/language_server/context.h b/toolchain/language_server/context.h
index 1f4b813a64bc..ed80d18ecd5a 100644
--- a/toolchain/language_server/context.h
+++ b/toolchain/language_server/context.h
@@ -15,7 +15,9 @@
 #include "toolchain/diagnostics/consumer.h"
 #include "toolchain/diagnostics/emitter.h"
 #include "toolchain/diagnostics/file_diagnostics.h"
+#include "toolchain/driver/codegen_options.h"
 #include "toolchain/driver/compile_driver.h"
+#include "toolchain/driver/compile_options.h"
 #include "toolchain/lex/tokenized_buffer.h"
 #include "toolchain/parse/tree_and_subtrees.h"
 #include "toolchain/sem_ir/file.h"
@@ -29,7 +31,9 @@ class Context {
   class File {
    public:
     explicit File(clang::clangd::URIForFile uri)
-        : uri_(std::move(uri)), filename_(uri_.file().str()) {}
+        : uri_(std::move(uri)),
+          filename_(uri_.file().str()),
+          options_(&codegen_options_) {}
 
     // Changes the file's text, updating dependent state.
     auto SetText(Context& context, std::optional<int64_t> version,
@@ -51,6 +55,8 @@ class Context {
 
     // Current file content, and derived values.
     std::string text_;
+
+    CodegenOptions codegen_options_;
     CompileOptions options_;
     std::unique_ptr<CompileDriver> compile_driver_;
   };
diff --git a/toolchain/lower/testdata/builtins/print_read.carbon b/toolchain/lower/testdata/builtins/print_read.carbon
index 7dfbd5771677..ebccf4912b20 100644
--- a/toolchain/lower/testdata/builtins/print_read.carbon
+++ b/toolchain/lower/testdata/builtins/print_read.carbon
@@ -2,6 +2,7 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
+// EXTRA-ARGS: --include-carbon-core
 // INCLUDE-FILE: toolchain/testing/testdata/min_prelude/full.carbon
 //
 // AUTOUPDATE
@@ -41,16 +42,16 @@ fn Main() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: while.cond:                                       ; preds = %if.else, %entry
 // CHECK:STDOUT:   %ReadChar.call = call i32 @getchar(), !dbg !9
-// CHECK:STDOUT:   %Int.as.EqWith.impl.NotEqual.call.loc22 = icmp ne i32 %ReadChar.call, -1, !dbg !9
-// CHECK:STDOUT:   br i1 %Int.as.EqWith.impl.NotEqual.call.loc22, label %while.body, label %while.done, !dbg !8
+// CHECK:STDOUT:   %Int.as.EqWith.impl.NotEqual.call.loc23 = icmp ne i32 %ReadChar.call, -1, !dbg !9
+// CHECK:STDOUT:   br i1 %Int.as.EqWith.impl.NotEqual.call.loc23, label %while.body, label %while.done, !dbg !8
 // CHECK:STDOUT:
 // CHECK:STDOUT: while.body:                                       ; preds = %while.cond
-// CHECK:STDOUT:   %PrintChar.call.loc24 = call i32 @putchar(i32 72), !dbg !10
-// CHECK:STDOUT:   %Int.as.EqWith.impl.NotEqual.call.loc24 = icmp ne i32 %PrintChar.call.loc24, -1, !dbg !10
-// CHECK:STDOUT:   br i1 %Int.as.EqWith.impl.NotEqual.call.loc24, label %if.then, label %if.else, !dbg !11
+// CHECK:STDOUT:   %PrintChar.call.loc25 = call i32 @putchar(i32 72), !dbg !10
+// CHECK:STDOUT:   %Int.as.EqWith.impl.NotEqual.call.loc25 = icmp ne i32 %PrintChar.call.loc25, -1, !dbg !10
+// CHECK:STDOUT:   br i1 %Int.as.EqWith.impl.NotEqual.call.loc25, label %if.then, label %if.else, !dbg !11
 // CHECK:STDOUT:
 // CHECK:STDOUT: if.then:                                          ; preds = %while.body
-// CHECK:STDOUT:   %PrintChar.call.loc25 = call i32 @putchar(i32 105), !dbg !12
+// CHECK:STDOUT:   %PrintChar.call.loc26 = call i32 @putchar(i32 105), !dbg !12
 // CHECK:STDOUT:   br label %if.else, !dbg !13
 // CHECK:STDOUT:
 // CHECK:STDOUT: if.else:                                          ; preds = %if.then, %while.body
@@ -78,16 +79,16 @@ fn Main() {
 // CHECK:STDOUT: !1 = !DIFile(filename: "print_read.carbon", directory: "")
 // CHECK:STDOUT: !2 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !3 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !4 = distinct !DISubprogram(name: "Main", linkageName: "_CMain.Main", scope: null, file: !1, line: 18, type: !5, spFlags: DISPFlagDefinition, unit: !0)
+// CHECK:STDOUT: !4 = distinct !DISubprogram(name: "Main", linkageName: "_CMain.Main", scope: null, file: !1, line: 19, type: !5, spFlags: DISPFlagDefinition, unit: !0)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)
 // CHECK:STDOUT: !6 = !{null}
-// CHECK:STDOUT: !7 = !DILocation(line: 19, column: 3, scope: !4)
-// CHECK:STDOUT: !8 = !DILocation(line: 22, column: 9, scope: !4)
-// CHECK:STDOUT: !9 = !DILocation(line: 22, column: 10, scope: !4)
-// CHECK:STDOUT: !10 = !DILocation(line: 24, column: 9, scope: !4)
-// CHECK:STDOUT: !11 = !DILocation(line: 24, column: 8, scope: !4)
-// CHECK:STDOUT: !12 = !DILocation(line: 25, column: 7, scope: !4)
-// CHECK:STDOUT: !13 = !DILocation(line: 24, column: 5, scope: !4)
-// CHECK:STDOUT: !14 = !DILocation(line: 22, column: 3, scope: !4)
-// CHECK:STDOUT: !15 = !DILocation(line: 18, column: 1, scope: !4)
+// CHECK:STDOUT: !7 = !DILocation(line: 20, column: 3, scope: !4)
+// CHECK:STDOUT: !8 = !DILocation(line: 23, column: 9, scope: !4)
+// CHECK:STDOUT: !9 = !DILocation(line: 23, column: 10, scope: !4)
+// CHECK:STDOUT: !10 = !DILocation(line: 25, column: 9, scope: !4)
+// CHECK:STDOUT: !11 = !DILocation(line: 25, column: 8, scope: !4)
+// CHECK:STDOUT: !12 = !DILocation(line: 26, column: 7, scope: !4)
+// CHECK:STDOUT: !13 = !DILocation(line: 25, column: 5, scope: !4)
+// CHECK:STDOUT: !14 = !DILocation(line: 23, column: 3, scope: !4)
+// CHECK:STDOUT: !15 = !DILocation(line: 19, column: 1, scope: !4)
 // CHECK:STDOUT:
diff --git a/toolchain/lower/testdata/for/break_continue.carbon b/toolchain/lower/testdata/for/break_continue.carbon
index 0a622893b574..c548803b8eb8 100644
--- a/toolchain/lower/testdata/for/break_continue.carbon
+++ b/toolchain/lower/testdata/for/break_continue.carbon
@@ -2,6 +2,7 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
+// EXTRA-ARGS: --include-carbon-core
 // INCLUDE-FILE: toolchain/testing/testdata/min_prelude/full.carbon
 //
 // AUTOUPDATE
@@ -37,47 +38,47 @@ fn For() {
 // CHECK:STDOUT: ; Function Attrs: nounwind
 // CHECK:STDOUT: define void @_CFor.Main() #0 !dbg !4 {
 // CHECK:STDOUT: entry:
-// CHECK:STDOUT:   %.loc20_32.1.temp = alloca { i32, i32 }, align 4, !dbg !7
+// CHECK:STDOUT:   %.loc21_32.1.temp = alloca { i32, i32 }, align 4, !dbg !7
 // CHECK:STDOUT:   %var = alloca i32, align 4, !dbg !8
-// CHECK:STDOUT:   %.loc20_33.1.temp = alloca <{ i32, i1 }>, align 4, !dbg !8
-// CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %.loc20_32.1.temp), !dbg !7
-// CHECK:STDOUT:   call void @_CRange.Core(ptr %.loc20_32.1.temp, i32 100), !dbg !7
-// CHECK:STDOUT:   %IntRange.as.Iterate.impl.NewCursor.call = call i32 @"_CNewCursor.IntRange.9452f4c51951679b.Core:Iterate.Core.be1e879c1ad406d8"(ptr %.loc20_32.1.temp), !dbg !8
+// CHECK:STDOUT:   %.loc21_33.1.temp = alloca <{ i32, i1 }>, align 4, !dbg !8
+// CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %.loc21_32.1.temp), !dbg !7
+// CHECK:STDOUT:   call void @_CRange.Core(ptr %.loc21_32.1.temp, i32 100), !dbg !7
+// CHECK:STDOUT:   %IntRange.as.Iterate.impl.NewCursor.call = call i32 @"_CNewCursor.IntRange.9452f4c51951679b.Core:Iterate.Core.be1e879c1ad406d8"(ptr %.loc21_32.1.temp), !dbg !8
 // CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %var), !dbg !8
 // CHECK:STDOUT:   store i32 %IntRange.as.Iterate.impl.NewCursor.call, ptr %var, align 4, !dbg !8
 // CHECK:STDOUT:   br label %for.next, !dbg !8
 // CHECK:STDOUT:
-// CHECK:STDOUT: for.next:                                         ; preds = %if.else.loc22, %if.then.loc22, %entry
-// CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %.loc20_33.1.temp), !dbg !8
-// CHECK:STDOUT:   call void @"_CNext.IntRange.9452f4c51951679b.Core:Iterate.Core.be1e879c1ad406d8"(ptr %.loc20_33.1.temp, ptr %.loc20_32.1.temp, ptr %var), !dbg !8
-// CHECK:STDOUT:   %Optional.HasValue.call = call i1 @_CHasValue.Optional.Core.329ac87584bc77f7(ptr %.loc20_33.1.temp), !dbg !8
+// CHECK:STDOUT: for.next:                                         ; preds = %if.else.loc23, %if.then.loc23, %entry
+// CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %.loc21_33.1.temp), !dbg !8
+// CHECK:STDOUT:   call void @"_CNext.IntRange.9452f4c51951679b.Core:Iterate.Core.be1e879c1ad406d8"(ptr %.loc21_33.1.temp, ptr %.loc21_32.1.temp, ptr %var), !dbg !8
+// CHECK:STDOUT:   %Optional.HasValue.call = call i1 @_CHasValue.Optional.Core.329ac87584bc77f7(ptr %.loc21_33.1.temp), !dbg !8
 // CHECK:STDOUT:   br i1 %Optional.HasValue.call, label %for.body, label %for.done, !dbg !8
 // CHECK:STDOUT:
 // CHECK:STDOUT: for.body:                                         ; preds = %for.next
-// CHECK:STDOUT:   %Optional.Get.call = call i32 @_CGet.Optional.Core.329ac87584bc77f7(ptr %.loc20_33.1.temp), !dbg !8
+// CHECK:STDOUT:   %Optional.Get.call = call i32 @_CGet.Optional.Core.329ac87584bc77f7(ptr %.loc21_33.1.temp), !dbg !8
 // CHECK:STDOUT:   %F.call = call i1 @_CF.Main(), !dbg !9
-// CHECK:STDOUT:   br i1 %F.call, label %if.then.loc21, label %if.else.loc21, !dbg !10
+// CHECK:STDOUT:   br i1 %F.call, label %if.then.loc22, label %if.else.loc22, !dbg !10
 // CHECK:STDOUT:
-// CHECK:STDOUT: if.then.loc21:                                    ; preds = %for.body
+// CHECK:STDOUT: if.then.loc22:                                    ; preds = %for.body
 // CHECK:STDOUT:   br label %for.done, !dbg !11
 // CHECK:STDOUT:
-// CHECK:STDOUT: if.else.loc21:                                    ; preds = %for.body
+// CHECK:STDOUT: if.else.loc22:                                    ; preds = %for.body
 // CHECK:STDOUT:   %G.call = call i1 @_CG.Main(), !dbg !12
-// CHECK:STDOUT:   br i1 %G.call, label %if.then.loc22, label %if.else.loc22, !dbg !13
+// CHECK:STDOUT:   br i1 %G.call, label %if.then.loc23, label %if.else.loc23, !dbg !13
 // CHECK:STDOUT:
-// CHECK:STDOUT: if.then.loc22:                                    ; preds = %if.else.loc21
-// CHECK:STDOUT:   call void @"_COp.f9d363db90f1ff8b:core.Destroy.Core"(ptr %.loc20_33.1.temp), !dbg !8
+// CHECK:STDOUT: if.then.loc23:                                    ; preds = %if.else.loc22
+// CHECK:STDOUT:   call void @"_COp.f9d363db90f1ff8b:core.Destroy.Core"(ptr %.loc21_33.1.temp), !dbg !8
 // CHECK:STDOUT:   br label %for.next, !dbg !14
 // CHECK:STDOUT:
-// CHECK:STDOUT: if.else.loc22:                                    ; preds = %if.else.loc21
+// CHECK:STDOUT: if.else.loc23:                                    ; preds = %if.else.loc22
 // CHECK:STDOUT:   call void @_CH.Main(), !dbg !15
-// CHECK:STDOUT:   call void @"_COp.f9d363db90f1ff8b:core.Destroy.Core"(ptr %.loc20_33.1.temp), !dbg !8
+// CHECK:STDOUT:   call void @"_COp.f9d363db90f1ff8b:core.Destroy.Core"(ptr %.loc21_33.1.temp), !dbg !8
 // CHECK:STDOUT:   br label %for.next, !dbg !16
 // CHECK:STDOUT:
-// CHECK:STDOUT: for.done:                                         ; preds = %if.then.loc21, %for.next
-// CHECK:STDOUT:   call void @"_COp.f9d363db90f1ff8b:core.Destroy.Core"(ptr %.loc20_33.1.temp), !dbg !8
+// CHECK:STDOUT: for.done:                                         ; preds = %if.then.loc22, %for.next
+// CHECK:STDOUT:   call void @"_COp.f9d363db90f1ff8b:core.Destroy.Core"(ptr %.loc21_33.1.temp), !dbg !8
 // CHECK:STDOUT:   call void @"_COp.5e27612b9dd31a14:core.Destroy.Core"(ptr %var), !dbg !8
-// CHECK:STDOUT:   call void @"_COp.0d5da2659ce22e5f:core.Destroy.Core"(ptr %.loc20_32.1.temp), !dbg !7
+// CHECK:STDOUT:   call void @"_COp.0d5da2659ce22e5f:core.Destroy.Core"(ptr %.loc21_32.1.temp), !dbg !7
 // CHECK:STDOUT:   ret void, !dbg !17
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
@@ -268,83 +269,83 @@ fn For() {
 // CHECK:STDOUT: !1 = !DIFile(filename: "break_continue.carbon", directory: "")
 // CHECK:STDOUT: !2 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !3 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !4 = distinct !DISubprogram(name: "For", linkageName: "_CFor.Main", scope: null, file: !1, line: 19, type: !5, spFlags: DISPFlagDefinition, unit: !0)
+// CHECK:STDOUT: !4 = distinct !DISubprogram(name: "For", linkageName: "_CFor.Main", scope: null, file: !1, line: 20, type: !5, spFlags: DISPFlagDefinition, unit: !0)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)
 // CHECK:STDOUT: !6 = !{null}
-// CHECK:STDOUT: !7 = !DILocation(line: 20, column: 18, scope: !4)
-// CHECK:STDOUT: !8 = !DILocation(line: 20, column: 7, scope: !4)
-// CHECK:STDOUT: !9 = !DILocation(line: 21, column: 9, scope: !4)
-// CHECK:STDOUT: !10 = !DILocation(line: 21, column: 8, scope: !4)
-// CHECK:STDOUT: !11 = !DILocation(line: 21, column: 16, scope: !4)
-// CHECK:STDOUT: !12 = !DILocation(line: 22, column: 9, scope: !4)
-// CHECK:STDOUT: !13 = !DILocation(line: 22, column: 8, scope: !4)
-// CHECK:STDOUT: !14 = !DILocation(line: 22, column: 16, scope: !4)
-// CHECK:STDOUT: !15 = !DILocation(line: 23, column: 5, scope: !4)
-// CHECK:STDOUT: !16 = !DILocation(line: 20, column: 3, scope: !4)
-// CHECK:STDOUT: !17 = !DILocation(line: 19, column: 1, scope: !4)
-// CHECK:STDOUT: !18 = distinct !DISubprogram(name: "Op", linkageName: "_COp.5e27612b9dd31a14:core.Destroy.Core", scope: null, file: !19, line: 24, type: !20, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !23)
+// CHECK:STDOUT: !7 = !DILocation(line: 21, column: 18, scope: !4)
+// CHECK:STDOUT: !8 = !DILocation(line: 21, column: 7, scope: !4)
+// CHECK:STDOUT: !9 = !DILocation(line: 22, column: 9, scope: !4)
+// CHECK:STDOUT: !10 = !DILocation(line: 22, column: 8, scope: !4)
+// CHECK:STDOUT: !11 = !DILocation(line: 22, column: 16, scope: !4)
+// CHECK:STDOUT: !12 = !DILocation(line: 23, column: 9, scope: !4)
+// CHECK:STDOUT: !13 = !DILocation(line: 23, column: 8, scope: !4)
+// CHECK:STDOUT: !14 = !DILocation(line: 23, column: 16, scope: !4)
+// CHECK:STDOUT: !15 = !DILocation(line: 24, column: 5, scope: !4)
+// CHECK:STDOUT: !16 = !DILocation(line: 21, column: 3, scope: !4)
+// CHECK:STDOUT: !17 = !DILocation(line: 20, column: 1, scope: !4)
+// CHECK:STDOUT: !18 = distinct !DISubprogram(name: "Op", linkageName: "_COp.5e27612b9dd31a14:core.Destroy.Core", scope: null, file: !19, line: 15, type: !20, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !23)
 // CHECK:STDOUT: !19 = !DIFile(filename: "{{.*}}/range.carbon", directory: "")
 // CHECK:STDOUT: !20 = !DISubroutineType(types: !21)
 // CHECK:STDOUT: !21 = !{null, !22}
 // CHECK:STDOUT: !22 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
 // CHECK:STDOUT: !23 = !{!24}
 // CHECK:STDOUT: !24 = !DILocalVariable(arg: 1, scope: !18, type: !22)
-// CHECK:STDOUT: !25 = !DILocation(line: 24, column: 39, scope: !18)
-// CHECK:STDOUT: !26 = distinct !DISubprogram(name: "Op", linkageName: "_COp.94ba1c30d421702e:core.Destroy.Core", scope: null, file: !1, line: 20, type: !27, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !30)
+// CHECK:STDOUT: !25 = !DILocation(line: 15, column: 39, scope: !18)
+// CHECK:STDOUT: !26 = distinct !DISubprogram(name: "Op", linkageName: "_COp.94ba1c30d421702e:core.Destroy.Core", scope: null, file: !1, line: 21, type: !27, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !30)
 // CHECK:STDOUT: !27 = !DISubroutineType(types: !28)
 // CHECK:STDOUT: !28 = !{null, !29}
 // CHECK:STDOUT: !29 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: null, size: 64)
 // CHECK:STDOUT: !30 = !{!31}
 // CHECK:STDOUT: !31 = !DILocalVariable(arg: 1, scope: !26, type: !29)
-// CHECK:STDOUT: !32 = !DILocation(line: 20, column: 7, scope: !26)
-// CHECK:STDOUT: !33 = distinct !DISubprogram(name: "Op", linkageName: "_COp.0fc9634857315db2:core.Destroy.Core", scope: null, file: !1, line: 20, type: !20, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !34)
+// CHECK:STDOUT: !32 = !DILocation(line: 21, column: 7, scope: !26)
+// CHECK:STDOUT: !33 = distinct !DISubprogram(name: "Op", linkageName: "_COp.0fc9634857315db2:core.Destroy.Core", scope: null, file: !1, line: 21, type: !20, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !34)
 // CHECK:STDOUT: !34 = !{!35}
 // CHECK:STDOUT: !35 = !DILocalVariable(arg: 1, scope: !33, type: !22)
-// CHECK:STDOUT: !36 = !DILocation(line: 20, column: 7, scope: !33)
-// CHECK:STDOUT: !37 = distinct !DISubprogram(name: "Op", linkageName: "_COp.69700c1fc1b2744c:core.Destroy.Core", scope: null, file: !1, line: 20, type: !27, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !38)
+// CHECK:STDOUT: !36 = !DILocation(line: 21, column: 7, scope: !33)
+// CHECK:STDOUT: !37 = distinct !DISubprogram(name: "Op", linkageName: "_COp.69700c1fc1b2744c:core.Destroy.Core", scope: null, file: !1, line: 21, type: !27, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !38)
 // CHECK:STDOUT: !38 = !{!39}
 // CHECK:STDOUT: !39 = !DILocalVariable(arg: 1, scope: !37, type: !29)
-// CHECK:STDOUT: !40 = !DILocation(line: 20, column: 7, scope: !37)
-// CHECK:STDOUT: !41 = distinct !DISubprogram(name: "Op", linkageName: "_COp.278d9a31079e7ff2:core.Destroy.Core", scope: null, file: !1, line: 20, type: !27, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !42)
+// CHECK:STDOUT: !40 = !DILocation(line: 21, column: 7, scope: !37)
+// CHECK:STDOUT: !41 = distinct !DISubprogram(name: "Op", linkageName: "_COp.278d9a31079e7ff2:core.Destroy.Core", scope: null, file: !1, line: 21, type: !27, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !42)
 // CHECK:STDOUT: !42 = !{!43}
 // CHECK:STDOUT: !43 = !DILocalVariable(arg: 1, scope: !41, type: !29)
-// CHECK:STDOUT: !44 = !DILocation(line: 20, column: 7, scope: !41)
-// CHECK:STDOUT: !45 = distinct !DISubprogram(name: "Op", linkageName: "_COp.f9d363db90f1ff8b:core.Destroy.Core", scope: null, file: !1, line: 20, type: !27, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !46)
+// CHECK:STDOUT: !44 = !DILocation(line: 21, column: 7, scope: !41)
+// CHECK:STDOUT: !45 = distinct !DISubprogram(name: "Op", linkageName: "_COp.f9d363db90f1ff8b:core.Destroy.Core", scope: null, file: !1, line: 21, type: !27, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !46)
 // CHECK:STDOUT: !46 = !{!47}
 // CHECK:STDOUT: !47 = !DILocalVariable(arg: 1, scope: !45, type: !29)
-// CHECK:STDOUT: !48 = !DILocation(line: 20, column: 7, scope: !45)
-// CHECK:STDOUT: !49 = distinct !DISubprogram(name: "Op", linkageName: "_COp.db43fa38232c28dd:core.Destroy.Core", scope: null, file: !1, line: 20, type: !27, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !50)
+// CHECK:STDOUT: !48 = !DILocation(line: 21, column: 7, scope: !45)
+// CHECK:STDOUT: !49 = distinct !DISubprogram(name: "Op", linkageName: "_COp.db43fa38232c28dd:core.Destroy.Core", scope: null, file: !1, line: 21, type: !27, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !50)
 // CHECK:STDOUT: !50 = !{!51}
 // CHECK:STDOUT: !51 = !DILocalVariable(arg: 1, scope: !49, type: !29)
-// CHECK:STDOUT: !52 = !DILocation(line: 20, column: 18, scope: !49)
-// CHECK:STDOUT: !53 = distinct !DISubprogram(name: "Op", linkageName: "_COp.0d5da2659ce22e5f:core.Destroy.Core", scope: null, file: !1, line: 20, type: !27, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !54)
+// CHECK:STDOUT: !52 = !DILocation(line: 21, column: 18, scope: !49)
+// CHECK:STDOUT: !53 = distinct !DISubprogram(name: "Op", linkageName: "_COp.0d5da2659ce22e5f:core.Destroy.Core", scope: null, file: !1, line: 21, type: !27, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !54)
 // CHECK:STDOUT: !54 = !{!55}
 // CHECK:STDOUT: !55 = !DILocalVariable(arg: 1, scope: !53, type: !29)
-// CHECK:STDOUT: !56 = !DILocation(line: 20, column: 18, scope: !53)
-// CHECK:STDOUT: !57 = distinct !DISubprogram(name: "NewCursor", linkageName: "_CNewCursor.IntRange.9452f4c51951679b.Core:Iterate.Core.be1e879c1ad406d8", scope: null, file: !19, line: 25, type: !58, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !60)
+// CHECK:STDOUT: !56 = !DILocation(line: 21, column: 18, scope: !53)
+// CHECK:STDOUT: !57 = distinct !DISubprogram(name: "NewCursor", linkageName: "_CNewCursor.IntRange.9452f4c51951679b.Core:Iterate.Core.be1e879c1ad406d8", scope: null, file: !19, line: 16, type: !58, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !60)
 // CHECK:STDOUT: !58 = !DISubroutineType(types: !59)
 // CHECK:STDOUT: !59 = !{!22, !29}
 // CHECK:STDOUT: !60 = !{!61}
 // CHECK:STDOUT: !61 = !DILocalVariable(arg: 1, scope: !57, type: !29)
-// CHECK:STDOUT: !62 = !DILocation(line: 25, column: 43, scope: !57)
-// CHECK:STDOUT: !63 = !DILocation(line: 25, column: 36, scope: !57)
-// CHECK:STDOUT: !64 = distinct !DISubprogram(name: "Next", linkageName: "_CNext.IntRange.9452f4c51951679b.Core:Iterate.Core.be1e879c1ad406d8", scope: null, file: !19, line: 26, type: !65, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !67)
+// CHECK:STDOUT: !62 = !DILocation(line: 16, column: 43, scope: !57)
+// CHECK:STDOUT: !63 = !DILocation(line: 16, column: 36, scope: !57)
+// CHECK:STDOUT: !64 = distinct !DISubprogram(name: "Next", linkageName: "_CNext.IntRange.9452f4c51951679b.Core:Iterate.Core.be1e879c1ad406d8", scope: null, file: !19, line: 17, type: !65, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !67)
 // CHECK:STDOUT: !65 = !DISubroutineType(types: !66)
 // CHECK:STDOUT: !66 = !{!29, !29, !29}
 // CHECK:STDOUT: !67 = !{!68, !69}
 // CHECK:STDOUT: !68 = !DILocalVariable(arg: 1, scope: !64, type: !29)
 // CHECK:STDOUT: !69 = !DILocalVariable(arg: 2, scope: !64, type: !29)
-// CHECK:STDOUT: !70 = !DILocation(line: 27, column: 7, scope: !64)
-// CHECK:STDOUT: !71 = !DILocation(line: 27, column: 27, scope: !64)
-// CHECK:STDOUT: !72 = !DILocation(line: 28, column: 19, scope: !64)
-// CHECK:STDOUT: !73 = !DILocation(line: 28, column: 11, scope: !64)
-// CHECK:STDOUT: !74 = !DILocation(line: 28, column: 10, scope: !64)
-// CHECK:STDOUT: !75 = !DILocation(line: 29, column: 9, scope: !64)
-// CHECK:STDOUT: !76 = !DILocation(line: 30, column: 38, scope: !64)
-// CHECK:STDOUT: !77 = !DILocation(line: 30, column: 16, scope: !64)
-// CHECK:STDOUT: !78 = !DILocation(line: 30, column: 9, scope: !64)
-// CHECK:STDOUT: !79 = !DILocation(line: 32, column: 16, scope: !64)
-// CHECK:STDOUT: !80 = !DILocation(line: 32, column: 9, scope: !64)
+// CHECK:STDOUT: !70 = !DILocation(line: 18, column: 7, scope: !64)
+// CHECK:STDOUT: !71 = !DILocation(line: 18, column: 27, scope: !64)
+// CHECK:STDOUT: !72 = !DILocation(line: 19, column: 19, scope: !64)
+// CHECK:STDOUT: !73 = !DILocation(line: 19, column: 11, scope: !64)
+// CHECK:STDOUT: !74 = !DILocation(line: 19, column: 10, scope: !64)
+// CHECK:STDOUT: !75 = !DILocation(line: 20, column: 9, scope: !64)
+// CHECK:STDOUT: !76 = !DILocation(line: 21, column: 38, scope: !64)
+// CHECK:STDOUT: !77 = !DILocation(line: 21, column: 16, scope: !64)
+// CHECK:STDOUT: !78 = !DILocation(line: 21, column: 9, scope: !64)
+// CHECK:STDOUT: !79 = !DILocation(line: 23, column: 16, scope: !64)
+// CHECK:STDOUT: !80 = !DILocation(line: 23, column: 9, scope: !64)
 // CHECK:STDOUT: !81 = distinct !DISubprogram(name: "HasValue", linkageName: "_CHasValue.Optional.Core.329ac87584bc77f7", scope: null, file: !82, line: 36, type: !83, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !85)
 // CHECK:STDOUT: !82 = !DIFile(filename: "{{.*}}/prelude/types/optional.carbon", directory: "")
 // CHECK:STDOUT: !83 = !DISubroutineType(types: !84)
diff --git a/toolchain/lower/testdata/for/for.carbon b/toolchain/lower/testdata/for/for.carbon
index c8a8dd6048a2..66cdab5f47dc 100644
--- a/toolchain/lower/testdata/for/for.carbon
+++ b/toolchain/lower/testdata/for/for.carbon
@@ -2,6 +2,7 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
+// EXTRA-ARGS: --include-carbon-core
 // INCLUDE-FILE: toolchain/testing/testdata/min_prelude/full.carbon
 //
 // AUTOUPDATE
@@ -37,33 +38,33 @@ fn For() {
 // CHECK:STDOUT: ; Function Attrs: nounwind
 // CHECK:STDOUT: define void @_CFor.Main() #0 !dbg !4 {
 // CHECK:STDOUT: entry:
-// CHECK:STDOUT:   %.loc21_32.1.temp = alloca { i32, i32 }, align 4, !dbg !7
+// CHECK:STDOUT:   %.loc22_32.1.temp = alloca { i32, i32 }, align 4, !dbg !7
 // CHECK:STDOUT:   %var = alloca i32, align 4, !dbg !8
-// CHECK:STDOUT:   %.loc21_33.1.temp = alloca <{ i32, i1 }>, align 4, !dbg !8
+// CHECK:STDOUT:   %.loc22_33.1.temp = alloca <{ i32, i1 }>, align 4, !dbg !8
 // CHECK:STDOUT:   call void @_CF.Main(), !dbg !9
-// CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %.loc21_32.1.temp), !dbg !7
-// CHECK:STDOUT:   call void @_CRange.Core(ptr %.loc21_32.1.temp, i32 100), !dbg !7
-// CHECK:STDOUT:   %IntRange.as.Iterate.impl.NewCursor.call = call i32 @"_CNewCursor.IntRange.9452f4c51951679b.Core:Iterate.Core.be1e879c1ad406d8"(ptr %.loc21_32.1.temp), !dbg !8
+// CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %.loc22_32.1.temp), !dbg !7
+// CHECK:STDOUT:   call void @_CRange.Core(ptr %.loc22_32.1.temp, i32 100), !dbg !7
+// CHECK:STDOUT:   %IntRange.as.Iterate.impl.NewCursor.call = call i32 @"_CNewCursor.IntRange.9452f4c51951679b.Core:Iterate.Core.be1e879c1ad406d8"(ptr %.loc22_32.1.temp), !dbg !8
 // CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %var), !dbg !8
 // CHECK:STDOUT:   store i32 %IntRange.as.Iterate.impl.NewCursor.call, ptr %var, align 4, !dbg !8
 // CHECK:STDOUT:   br label %for.next, !dbg !8
 // CHECK:STDOUT:
 // CHECK:STDOUT: for.next:                                         ; preds = %for.body, %entry
-// CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %.loc21_33.1.temp), !dbg !8
-// CHECK:STDOUT:   call void @"_CNext.IntRange.9452f4c51951679b.Core:Iterate.Core.be1e879c1ad406d8"(ptr %.loc21_33.1.temp, ptr %.loc21_32.1.temp, ptr %var), !dbg !8
-// CHECK:STDOUT:   %Optional.HasValue.call = call i1 @_CHasValue.Optional.Core.329ac87584bc77f7(ptr %.loc21_33.1.temp), !dbg !8
+// CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %.loc22_33.1.temp), !dbg !8
+// CHECK:STDOUT:   call void @"_CNext.IntRange.9452f4c51951679b.Core:Iterate.Core.be1e879c1ad406d8"(ptr %.loc22_33.1.temp, ptr %.loc22_32.1.temp, ptr %var), !dbg !8
+// CHECK:STDOUT:   %Optional.HasValue.call = call i1 @_CHasValue.Optional.Core.329ac87584bc77f7(ptr %.loc22_33.1.temp), !dbg !8
 // CHECK:STDOUT:   br i1 %Optional.HasValue.call, label %for.body, label %for.done, !dbg !8
 // CHECK:STDOUT:
 // CHECK:STDOUT: for.body:                                         ; preds = %for.next
-// CHECK:STDOUT:   %Optional.Get.call = call i32 @_CGet.Optional.Core.329ac87584bc77f7(ptr %.loc21_33.1.temp), !dbg !8
+// CHECK:STDOUT:   %Optional.Get.call = call i32 @_CGet.Optional.Core.329ac87584bc77f7(ptr %.loc22_33.1.temp), !dbg !8
 // CHECK:STDOUT:   call void @_CG.Main(), !dbg !10
-// CHECK:STDOUT:   call void @"_COp.f9d363db90f1ff8b:core.Destroy.Core"(ptr %.loc21_33.1.temp), !dbg !8
+// CHECK:STDOUT:   call void @"_COp.f9d363db90f1ff8b:core.Destroy.Core"(ptr %.loc22_33.1.temp), !dbg !8
 // CHECK:STDOUT:   br label %for.next, !dbg !11
 // CHECK:STDOUT:
 // CHECK:STDOUT: for.done:                                         ; preds = %for.next
-// CHECK:STDOUT:   call void @"_COp.f9d363db90f1ff8b:core.Destroy.Core"(ptr %.loc21_33.1.temp), !dbg !8
+// CHECK:STDOUT:   call void @"_COp.f9d363db90f1ff8b:core.Destroy.Core"(ptr %.loc22_33.1.temp), !dbg !8
 // CHECK:STDOUT:   call void @"_COp.5e27612b9dd31a14:core.Destroy.Core"(ptr %var), !dbg !8
-// CHECK:STDOUT:   call void @"_COp.0d5da2659ce22e5f:core.Destroy.Core"(ptr %.loc21_32.1.temp), !dbg !7
+// CHECK:STDOUT:   call void @"_COp.0d5da2659ce22e5f:core.Destroy.Core"(ptr %.loc22_32.1.temp), !dbg !7
 // CHECK:STDOUT:   call void @_CH.Main(), !dbg !12
 // CHECK:STDOUT:   ret void, !dbg !13
 // CHECK:STDOUT: }
@@ -255,79 +256,79 @@ fn For() {
 // CHECK:STDOUT: !1 = !DIFile(filename: "for.carbon", directory: "")
 // CHECK:STDOUT: !2 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !3 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !4 = distinct !DISubprogram(name: "For", linkageName: "_CFor.Main", scope: null, file: !1, line: 19, type: !5, spFlags: DISPFlagDefinition, unit: !0)
+// CHECK:STDOUT: !4 = distinct !DISubprogram(name: "For", linkageName: "_CFor.Main", scope: null, file: !1, line: 20, type: !5, spFlags: DISPFlagDefinition, unit: !0)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)
 // CHECK:STDOUT: !6 = !{null}
-// CHECK:STDOUT: !7 = !DILocation(line: 21, column: 18, scope: !4)
-// CHECK:STDOUT: !8 = !DILocation(line: 21, column: 7, scope: !4)
-// CHECK:STDOUT: !9 = !DILocation(line: 20, column: 3, scope: !4)
-// CHECK:STDOUT: !10 = !DILocation(line: 22, column: 5, scope: !4)
-// CHECK:STDOUT: !11 = !DILocation(line: 21, column: 3, scope: !4)
-// CHECK:STDOUT: !12 = !DILocation(line: 24, column: 3, scope: !4)
-// CHECK:STDOUT: !13 = !DILocation(line: 19, column: 1, scope: !4)
-// CHECK:STDOUT: !14 = distinct !DISubprogram(name: "Op", linkageName: "_COp.5e27612b9dd31a14:core.Destroy.Core", scope: null, file: !15, line: 24, type: !16, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !19)
+// CHECK:STDOUT: !7 = !DILocation(line: 22, column: 18, scope: !4)
+// CHECK:STDOUT: !8 = !DILocation(line: 22, column: 7, scope: !4)
+// CHECK:STDOUT: !9 = !DILocation(line: 21, column: 3, scope: !4)
+// CHECK:STDOUT: !10 = !DILocation(line: 23, column: 5, scope: !4)
+// CHECK:STDOUT: !11 = !DILocation(line: 22, column: 3, scope: !4)
+// CHECK:STDOUT: !12 = !DILocation(line: 25, column: 3, scope: !4)
+// CHECK:STDOUT: !13 = !DILocation(line: 20, column: 1, scope: !4)
+// CHECK:STDOUT: !14 = distinct !DISubprogram(name: "Op", linkageName: "_COp.5e27612b9dd31a14:core.Destroy.Core", scope: null, file: !15, line: 15, type: !16, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !19)
 // CHECK:STDOUT: !15 = !DIFile(filename: "{{.*}}/range.carbon", directory: "")
 // CHECK:STDOUT: !16 = !DISubroutineType(types: !17)
 // CHECK:STDOUT: !17 = !{null, !18}
 // CHECK:STDOUT: !18 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
 // CHECK:STDOUT: !19 = !{!20}
 // CHECK:STDOUT: !20 = !DILocalVariable(arg: 1, scope: !14, type: !18)
-// CHECK:STDOUT: !21 = !DILocation(line: 24, column: 39, scope: !14)
-// CHECK:STDOUT: !22 = distinct !DISubprogram(name: "Op", linkageName: "_COp.94ba1c30d421702e:core.Destroy.Core", scope: null, file: !1, line: 21, type: !23, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !26)
+// CHECK:STDOUT: !21 = !DILocation(line: 15, column: 39, scope: !14)
+// CHECK:STDOUT: !22 = distinct !DISubprogram(name: "Op", linkageName: "_COp.94ba1c30d421702e:core.Destroy.Core", scope: null, file: !1, line: 22, type: !23, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !26)
 // CHECK:STDOUT: !23 = !DISubroutineType(types: !24)
 // CHECK:STDOUT: !24 = !{null, !25}
 // CHECK:STDOUT: !25 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: null, size: 64)
 // CHECK:STDOUT: !26 = !{!27}
 // CHECK:STDOUT: !27 = !DILocalVariable(arg: 1, scope: !22, type: !25)
-// CHECK:STDOUT: !28 = !DILocation(line: 21, column: 7, scope: !22)
-// CHECK:STDOUT: !29 = distinct !DISubprogram(name: "Op", linkageName: "_COp.0fc9634857315db2:core.Destroy.Core", scope: null, file: !1, line: 21, type: !16, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !30)
+// CHECK:STDOUT: !28 = !DILocation(line: 22, column: 7, scope: !22)
+// CHECK:STDOUT: !29 = distinct !DISubprogram(name: "Op", linkageName: "_COp.0fc9634857315db2:core.Destroy.Core", scope: null, file: !1, line: 22, type: !16, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !30)
 // CHECK:STDOUT: !30 = !{!31}
 // CHECK:STDOUT: !31 = !DILocalVariable(arg: 1, scope: !29, type: !18)
-// CHECK:STDOUT: !32 = !DILocation(line: 21, column: 7, scope: !29)
-// CHECK:STDOUT: !33 = distinct !DISubprogram(name: "Op", linkageName: "_COp.69700c1fc1b2744c:core.Destroy.Core", scope: null, file: !1, line: 21, type: !23, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !34)
+// CHECK:STDOUT: !32 = !DILocation(line: 22, column: 7, scope: !29)
+// CHECK:STDOUT: !33 = distinct !DISubprogram(name: "Op", linkageName: "_COp.69700c1fc1b2744c:core.Destroy.Core", scope: null, file: !1, line: 22, type: !23, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !34)
 // CHECK:STDOUT: !34 = !{!35}
 // CHECK:STDOUT: !35 = !DILocalVariable(arg: 1, scope: !33, type: !25)
-// CHECK:STDOUT: !36 = !DILocation(line: 21, column: 7, scope: !33)
-// CHECK:STDOUT: !37 = distinct !DISubprogram(name: "Op", linkageName: "_COp.278d9a31079e7ff2:core.Destroy.Core", scope: null, file: !1, line: 21, type: !23, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !38)
+// CHECK:STDOUT: !36 = !DILocation(line: 22, column: 7, scope: !33)
+// CHECK:STDOUT: !37 = distinct !DISubprogram(name: "Op", linkageName: "_COp.278d9a31079e7ff2:core.Destroy.Core", scope: null, file: !1, line: 22, type: !23, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !38)
 // CHECK:STDOUT: !38 = !{!39}
 // CHECK:STDOUT: !39 = !DILocalVariable(arg: 1, scope: !37, type: !25)
-// CHECK:STDOUT: !40 = !DILocation(line: 21, column: 7, scope: !37)
-// CHECK:STDOUT: !41 = distinct !DISubprogram(name: "Op", linkageName: "_COp.f9d363db90f1ff8b:core.Destroy.Core", scope: null, file: !1, line: 21, type: !23, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !42)
+// CHECK:STDOUT: !40 = !DILocation(line: 22, column: 7, scope: !37)
+// CHECK:STDOUT: !41 = distinct !DISubprogram(name: "Op", linkageName: "_COp.f9d363db90f1ff8b:core.Destroy.Core", scope: null, file: !1, line: 22, type: !23, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !42)
 // CHECK:STDOUT: !42 = !{!43}
 // CHECK:STDOUT: !43 = !DILocalVariable(arg: 1, scope: !41, type: !25)
-// CHECK:STDOUT: !44 = !DILocation(line: 21, column: 7, scope: !41)
-// CHECK:STDOUT: !45 = distinct !DISubprogram(name: "Op", linkageName: "_COp.db43fa38232c28dd:core.Destroy.Core", scope: null, file: !1, line: 21, type: !23, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !46)
+// CHECK:STDOUT: !44 = !DILocation(line: 22, column: 7, scope: !41)
+// CHECK:STDOUT: !45 = distinct !DISubprogram(name: "Op", linkageName: "_COp.db43fa38232c28dd:core.Destroy.Core", scope: null, file: !1, line: 22, type: !23, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !46)
 // CHECK:STDOUT: !46 = !{!47}
 // CHECK:STDOUT: !47 = !DILocalVariable(arg: 1, scope: !45, type: !25)
-// CHECK:STDOUT: !48 = !DILocation(line: 21, column: 18, scope: !45)
-// CHECK:STDOUT: !49 = distinct !DISubprogram(name: "Op", linkageName: "_COp.0d5da2659ce22e5f:core.Destroy.Core", scope: null, file: !1, line: 21, type: !23, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !50)
+// CHECK:STDOUT: !48 = !DILocation(line: 22, column: 18, scope: !45)
+// CHECK:STDOUT: !49 = distinct !DISubprogram(name: "Op", linkageName: "_COp.0d5da2659ce22e5f:core.Destroy.Core", scope: null, file: !1, line: 22, type: !23, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !50)
 // CHECK:STDOUT: !50 = !{!51}
 // CHECK:STDOUT: !51 = !DILocalVariable(arg: 1, scope: !49, type: !25)
-// CHECK:STDOUT: !52 = !DILocation(line: 21, column: 18, scope: !49)
-// CHECK:STDOUT: !53 = distinct !DISubprogram(name: "NewCursor", linkageName: "_CNewCursor.IntRange.9452f4c51951679b.Core:Iterate.Core.be1e879c1ad406d8", scope: null, file: !15, line: 25, type: !54, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !56)
+// CHECK:STDOUT: !52 = !DILocation(line: 22, column: 18, scope: !49)
+// CHECK:STDOUT: !53 = distinct !DISubprogram(name: "NewCursor", linkageName: "_CNewCursor.IntRange.9452f4c51951679b.Core:Iterate.Core.be1e879c1ad406d8", scope: null, file: !15, line: 16, type: !54, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !56)
 // CHECK:STDOUT: !54 = !DISubroutineType(types: !55)
 // CHECK:STDOUT: !55 = !{!18, !25}
 // CHECK:STDOUT: !56 = !{!57}
 // CHECK:STDOUT: !57 = !DILocalVariable(arg: 1, scope: !53, type: !25)
-// CHECK:STDOUT: !58 = !DILocation(line: 25, column: 43, scope: !53)
-// CHECK:STDOUT: !59 = !DILocation(line: 25, column: 36, scope: !53)
-// CHECK:STDOUT: !60 = distinct !DISubprogram(name: "Next", linkageName: "_CNext.IntRange.9452f4c51951679b.Core:Iterate.Core.be1e879c1ad406d8", scope: null, file: !15, line: 26, type: !61, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !63)
+// CHECK:STDOUT: !58 = !DILocation(line: 16, column: 43, scope: !53)
+// CHECK:STDOUT: !59 = !DILocation(line: 16, column: 36, scope: !53)
+// CHECK:STDOUT: !60 = distinct !DISubprogram(name: "Next", linkageName: "_CNext.IntRange.9452f4c51951679b.Core:Iterate.Core.be1e879c1ad406d8", scope: null, file: !15, line: 17, type: !61, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !63)
 // CHECK:STDOUT: !61 = !DISubroutineType(types: !62)
 // CHECK:STDOUT: !62 = !{!25, !25, !25}
 // CHECK:STDOUT: !63 = !{!64, !65}
 // CHECK:STDOUT: !64 = !DILocalVariable(arg: 1, scope: !60, type: !25)
 // CHECK:STDOUT: !65 = !DILocalVariable(arg: 2, scope: !60, type: !25)
-// CHECK:STDOUT: !66 = !DILocation(line: 27, column: 7, scope: !60)
-// CHECK:STDOUT: !67 = !DILocation(line: 27, column: 27, scope: !60)
-// CHECK:STDOUT: !68 = !DILocation(line: 28, column: 19, scope: !60)
-// CHECK:STDOUT: !69 = !DILocation(line: 28, column: 11, scope: !60)
-// CHECK:STDOUT: !70 = !DILocation(line: 28, column: 10, scope: !60)
-// CHECK:STDOUT: !71 = !DILocation(line: 29, column: 9, scope: !60)
-// CHECK:STDOUT: !72 = !DILocation(line: 30, column: 38, scope: !60)
-// CHECK:STDOUT: !73 = !DILocation(line: 30, column: 16, scope: !60)
-// CHECK:STDOUT: !74 = !DILocation(line: 30, column: 9, scope: !60)
-// CHECK:STDOUT: !75 = !DILocation(line: 32, column: 16, scope: !60)
-// CHECK:STDOUT: !76 = !DILocation(line: 32, column: 9, scope: !60)
+// CHECK:STDOUT: !66 = !DILocation(line: 18, column: 7, scope: !60)
+// CHECK:STDOUT: !67 = !DILocation(line: 18, column: 27, scope: !60)
+// CHECK:STDOUT: !68 = !DILocation(line: 19, column: 19, scope: !60)
+// CHECK:STDOUT: !69 = !DILocation(line: 19, column: 11, scope: !60)
+// CHECK:STDOUT: !70 = !DILocation(line: 19, column: 10, scope: !60)
+// CHECK:STDOUT: !71 = !DILocation(line: 20, column: 9, scope: !60)
+// CHECK:STDOUT: !72 = !DILocation(line: 21, column: 38, scope: !60)
+// CHECK:STDOUT: !73 = !DILocation(line: 21, column: 16, scope: !60)
+// CHECK:STDOUT: !74 = !DILocation(line: 21, column: 9, scope: !60)
+// CHECK:STDOUT: !75 = !DILocation(line: 23, column: 16, scope: !60)
+// CHECK:STDOUT: !76 = !DILocation(line: 23, column: 9, scope: !60)
 // CHECK:STDOUT: !77 = distinct !DISubprogram(name: "HasValue", linkageName: "_CHasValue.Optional.Core.329ac87584bc77f7", scope: null, file: !78, line: 36, type: !79, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !81)
 // CHECK:STDOUT: !78 = !DIFile(filename: "{{.*}}/prelude/types/optional.carbon", directory: "")
 // CHECK:STDOUT: !79 = !DISubroutineType(types: !80)
diff --git a/toolchain/lower/testdata/function/generic/call_different_impls.carbon b/toolchain/lower/testdata/function/generic/call_different_impls.carbon
index f5c5f5585430..bbc339bc0f02 100644
--- a/toolchain/lower/testdata/function/generic/call_different_impls.carbon
+++ b/toolchain/lower/testdata/function/generic/call_different_impls.carbon
@@ -2,6 +2,7 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
+// EXTRA-ARGS: --include-carbon-core
 // INCLUDE-FILE: toolchain/testing/testdata/min_prelude/full.carbon
 //
 // AUTOUPDATE
@@ -89,25 +90,25 @@ fn Run() {
 // CHECK:STDOUT: !1 = !DIFile(filename: "call_different_impls.carbon", directory: "")
 // CHECK:STDOUT: !2 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !3 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !4 = distinct !DISubprogram(name: "F", linkageName: "_CF.X.Main:I.Main", scope: null, file: !1, line: 20, type: !5, spFlags: DISPFlagDefinition, unit: !0)
+// CHECK:STDOUT: !4 = distinct !DISubprogram(name: "F", linkageName: "_CF.X.Main:I.Main", scope: null, file: !1, line: 21, type: !5, spFlags: DISPFlagDefinition, unit: !0)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)
 // CHECK:STDOUT: !6 = !{null}
-// CHECK:STDOUT: !7 = !DILocation(line: 20, column: 12, scope: !4)
-// CHECK:STDOUT: !8 = !DILocation(line: 20, column: 3, scope: !4)
-// CHECK:STDOUT: !9 = distinct !DISubprogram(name: "F", linkageName: "_CF.Y.Main:I.Main", scope: null, file: !1, line: 24, type: !5, spFlags: DISPFlagDefinition, unit: !0)
-// CHECK:STDOUT: !10 = !DILocation(line: 24, column: 12, scope: !9)
-// CHECK:STDOUT: !11 = !DILocation(line: 24, column: 3, scope: !9)
-// CHECK:STDOUT: !12 = distinct !DISubprogram(name: "Run", linkageName: "main", scope: null, file: !1, line: 31, type: !13, spFlags: DISPFlagDefinition, unit: !0)
+// CHECK:STDOUT: !7 = !DILocation(line: 21, column: 12, scope: !4)
+// CHECK:STDOUT: !8 = !DILocation(line: 21, column: 3, scope: !4)
+// CHECK:STDOUT: !9 = distinct !DISubprogram(name: "F", linkageName: "_CF.Y.Main:I.Main", scope: null, file: !1, line: 25, type: !5, spFlags: DISPFlagDefinition, unit: !0)
+// CHECK:STDOUT: !10 = !DILocation(line: 25, column: 12, scope: !9)
+// CHECK:STDOUT: !11 = !DILocation(line: 25, column: 3, scope: !9)
+// CHECK:STDOUT: !12 = distinct !DISubprogram(name: "Run", linkageName: "main", scope: null, file: !1, line: 32, type: !13, spFlags: DISPFlagDefinition, unit: !0)
 // CHECK:STDOUT: !13 = !DISubroutineType(types: !14)
 // CHECK:STDOUT: !14 = !{!15}
 // CHECK:STDOUT: !15 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
-// CHECK:STDOUT: !16 = !DILocation(line: 32, column: 3, scope: !12)
-// CHECK:STDOUT: !17 = !DILocation(line: 33, column: 3, scope: !12)
-// CHECK:STDOUT: !18 = !DILocation(line: 31, column: 1, scope: !12)
-// CHECK:STDOUT: !19 = distinct !DISubprogram(name: "G", linkageName: "_CG.Main.c81631f865470482", scope: null, file: !1, line: 29, type: !5, spFlags: DISPFlagDefinition, unit: !0)
-// CHECK:STDOUT: !20 = !DILocation(line: 29, column: 22, scope: !19)
-// CHECK:STDOUT: !21 = !DILocation(line: 29, column: 1, scope: !19)
-// CHECK:STDOUT: !22 = distinct !DISubprogram(name: "G", linkageName: "_CG.Main.0b241ec84a68877b", scope: null, file: !1, line: 29, type: !5, spFlags: DISPFlagDefinition, unit: !0)
-// CHECK:STDOUT: !23 = !DILocation(line: 29, column: 22, scope: !22)
-// CHECK:STDOUT: !24 = !DILocation(line: 29, column: 1, scope: !22)
+// CHECK:STDOUT: !16 = !DILocation(line: 33, column: 3, scope: !12)
+// CHECK:STDOUT: !17 = !DILocation(line: 34, column: 3, scope: !12)
+// CHECK:STDOUT: !18 = !DILocation(line: 32, column: 1, scope: !12)
+// CHECK:STDOUT: !19 = distinct !DISubprogram(name: "G", linkageName: "_CG.Main.c81631f865470482", scope: null, file: !1, line: 30, type: !5, spFlags: DISPFlagDefinition, unit: !0)
+// CHECK:STDOUT: !20 = !DILocation(line: 30, column: 22, scope: !19)
+// CHECK:STDOUT: !21 = !DILocation(line: 30, column: 1, scope: !19)
+// CHECK:STDOUT: !22 = distinct !DISubprogram(name: "G", linkageName: "_CG.Main.0b241ec84a68877b", scope: null, file: !1, line: 30, type: !5, spFlags: DISPFlagDefinition, unit: !0)
+// CHECK:STDOUT: !23 = !DILocation(line: 30, column: 22, scope: !22)
+// CHECK:STDOUT: !24 = !DILocation(line: 30, column: 1, scope: !22)
 // CHECK:STDOUT:
diff --git a/toolchain/lower/testdata/function/generic/call_different_impls_with_const.carbon b/toolchain/lower/testdata/function/generic/call_different_impls_with_const.carbon
index 60e6be94dc30..4cdb373967df 100644
--- a/toolchain/lower/testdata/function/generic/call_different_impls_with_const.carbon
+++ b/toolchain/lower/testdata/function/generic/call_different_impls_with_const.carbon
@@ -2,6 +2,7 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
+// EXTRA-ARGS: --include-carbon-core
 // INCLUDE-FILE: toolchain/testing/testdata/min_prelude/full.carbon
 //
 // AUTOUPDATE
@@ -81,25 +82,25 @@ fn Run() {
 // CHECK:STDOUT: ; Function Attrs: nounwind
 // CHECK:STDOUT: define linkonce_odr void @_CG.Main.e2c7a58ecf9ad23e() #0 !dbg !26 {
 // CHECK:STDOUT: entry:
-// CHECK:STDOUT:   %.loc37_20.1.temp = alloca i1, align 1, !dbg !29
-// CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %.loc37_20.1.temp), !dbg !29
+// CHECK:STDOUT:   %.loc38_20.1.temp = alloca i1, align 1, !dbg !29
+// CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %.loc38_20.1.temp), !dbg !29
 // CHECK:STDOUT:   %I.WithSelf.F.call = call i1 @"_CF.X.Main:I.Main"(), !dbg !29
-// CHECK:STDOUT:   %.loc37_20.2 = zext i1 %I.WithSelf.F.call to i8, !dbg !29
-// CHECK:STDOUT:   store i8 %.loc37_20.2, ptr %.loc37_20.1.temp, align 1, !dbg !29
-// CHECK:STDOUT:   %.loc37_20.3 = load i8, ptr %.loc37_20.1.temp, align 1, !dbg !29
-// CHECK:STDOUT:   %.loc37_20.31 = trunc i8 %.loc37_20.3 to i1, !dbg !29
+// CHECK:STDOUT:   %.loc38_20.2 = zext i1 %I.WithSelf.F.call to i8, !dbg !29
+// CHECK:STDOUT:   store i8 %.loc38_20.2, ptr %.loc38_20.1.temp, align 1, !dbg !29
+// CHECK:STDOUT:   %.loc38_20.3 = load i8, ptr %.loc38_20.1.temp, align 1, !dbg !29
+// CHECK:STDOUT:   %.loc38_20.31 = trunc i8 %.loc38_20.3 to i1, !dbg !29
 // CHECK:STDOUT:   ret void, !dbg !30
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nounwind
 // CHECK:STDOUT: define linkonce_odr void @_CG.Main.01a101e5421592ac() #0 !dbg !31 {
 // CHECK:STDOUT: entry:
-// CHECK:STDOUT:   %.loc37_20.1.temp = alloca i32, align 4, !dbg !32
-// CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %.loc37_20.1.temp), !dbg !32
+// CHECK:STDOUT:   %.loc38_20.1.temp = alloca i32, align 4, !dbg !32
+// CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %.loc38_20.1.temp), !dbg !32
 // CHECK:STDOUT:   %I.WithSelf.F.call = call i32 @"_CF.Y.Main:I.Main"(), !dbg !32
-// CHECK:STDOUT:   store i32 %I.WithSelf.F.call, ptr %.loc37_20.1.temp, align 4, !dbg !32
-// CHECK:STDOUT:   %.loc37_20.3 = load i32, ptr %.loc37_20.1.temp, align 4, !dbg !32
-// CHECK:STDOUT:   call void @"_COp.5e27612b9dd31a14:core.Destroy.Core"(ptr %.loc37_20.1.temp), !dbg !32
+// CHECK:STDOUT:   store i32 %I.WithSelf.F.call, ptr %.loc38_20.1.temp, align 4, !dbg !32
+// CHECK:STDOUT:   %.loc38_20.3 = load i32, ptr %.loc38_20.1.temp, align 4, !dbg !32
+// CHECK:STDOUT:   call void @"_COp.5e27612b9dd31a14:core.Destroy.Core"(ptr %.loc38_20.1.temp), !dbg !32
 // CHECK:STDOUT:   ret void, !dbg !33
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
@@ -120,34 +121,34 @@ fn Run() {
 // CHECK:STDOUT: !1 = !DIFile(filename: "call_different_impls_with_const.carbon", directory: "")
 // CHECK:STDOUT: !2 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !3 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !4 = distinct !DISubprogram(name: "F", linkageName: "_CF.X.Main:I.Main", scope: null, file: !1, line: 21, type: !5, spFlags: DISPFlagDefinition, unit: !0)
+// CHECK:STDOUT: !4 = distinct !DISubprogram(name: "F", linkageName: "_CF.X.Main:I.Main", scope: null, file: !1, line: 22, type: !5, spFlags: DISPFlagDefinition, unit: !0)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)
 // CHECK:STDOUT: !6 = !{!7}
 // CHECK:STDOUT: !7 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: null, size: 64)
-// CHECK:STDOUT: !8 = !DILocation(line: 22, column: 5, scope: !4)
-// CHECK:STDOUT: !9 = !DILocation(line: 23, column: 5, scope: !4)
-// CHECK:STDOUT: !10 = distinct !DISubprogram(name: "Op", linkageName: "_COp.5e27612b9dd31a14:core.Destroy.Core", scope: null, file: !1, line: 27, type: !11, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !14)
+// CHECK:STDOUT: !8 = !DILocation(line: 23, column: 5, scope: !4)
+// CHECK:STDOUT: !9 = !DILocation(line: 24, column: 5, scope: !4)
+// CHECK:STDOUT: !10 = distinct !DISubprogram(name: "Op", linkageName: "_COp.5e27612b9dd31a14:core.Destroy.Core", scope: null, file: !1, line: 28, type: !11, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !14)
 // CHECK:STDOUT: !11 = !DISubroutineType(types: !12)
 // CHECK:STDOUT: !12 = !{null, !13}
 // CHECK:STDOUT: !13 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
 // CHECK:STDOUT: !14 = !{!15}
 // CHECK:STDOUT: !15 = !DILocalVariable(arg: 1, scope: !10, type: !13)
-// CHECK:STDOUT: !16 = !DILocation(line: 27, column: 24, scope: !10)
-// CHECK:STDOUT: !17 = distinct !DISubprogram(name: "F", linkageName: "_CF.Y.Main:I.Main", scope: null, file: !1, line: 28, type: !18, spFlags: DISPFlagDefinition, unit: !0)
+// CHECK:STDOUT: !16 = !DILocation(line: 28, column: 24, scope: !10)
+// CHECK:STDOUT: !17 = distinct !DISubprogram(name: "F", linkageName: "_CF.Y.Main:I.Main", scope: null, file: !1, line: 29, type: !18, spFlags: DISPFlagDefinition, unit: !0)
 // CHECK:STDOUT: !18 = !DISubroutineType(types: !19)
 // CHECK:STDOUT: !19 = !{!13}
-// CHECK:STDOUT: !20 = !DILocation(line: 29, column: 5, scope: !17)
-// CHECK:STDOUT: !21 = !DILocation(line: 30, column: 5, scope: !17)
-// CHECK:STDOUT: !22 = distinct !DISubprogram(name: "Run", linkageName: "main", scope: null, file: !1, line: 40, type: !18, spFlags: DISPFlagDefinition, unit: !0)
-// CHECK:STDOUT: !23 = !DILocation(line: 41, column: 3, scope: !22)
-// CHECK:STDOUT: !24 = !DILocation(line: 42, column: 3, scope: !22)
-// CHECK:STDOUT: !25 = !DILocation(line: 40, column: 1, scope: !22)
-// CHECK:STDOUT: !26 = distinct !DISubprogram(name: "G", linkageName: "_CG.Main.e2c7a58ecf9ad23e", scope: null, file: !1, line: 36, type: !27, spFlags: DISPFlagDefinition, unit: !0)
+// CHECK:STDOUT: !20 = !DILocation(line: 30, column: 5, scope: !17)
+// CHECK:STDOUT: !21 = !DILocation(line: 31, column: 5, scope: !17)
+// CHECK:STDOUT: !22 = distinct !DISubprogram(name: "Run", linkageName: "main", scope: null, file: !1, line: 41, type: !18, spFlags: DISPFlagDefinition, unit: !0)
+// CHECK:STDOUT: !23 = !DILocation(line: 42, column: 3, scope: !22)
+// CHECK:STDOUT: !24 = !DILocation(line: 43, column: 3, scope: !22)
+// CHECK:STDOUT: !25 = !DILocation(line: 41, column: 1, scope: !22)
+// CHECK:STDOUT: !26 = distinct !DISubprogram(name: "G", linkageName: "_CG.Main.e2c7a58ecf9ad23e", scope: null, file: !1, line: 37, type: !27, spFlags: DISPFlagDefinition, unit: !0)
 // CHECK:STDOUT: !27 = !DISubroutineType(types: !28)
 // CHECK:STDOUT: !28 = !{null}
-// CHECK:STDOUT: !29 = !DILocation(line: 37, column: 16, scope: !26)
-// CHECK:STDOUT: !30 = !DILocation(line: 36, column: 1, scope: !26)
-// CHECK:STDOUT: !31 = distinct !DISubprogram(name: "G", linkageName: "_CG.Main.01a101e5421592ac", scope: null, file: !1, line: 36, type: !27, spFlags: DISPFlagDefinition, unit: !0)
-// CHECK:STDOUT: !32 = !DILocation(line: 37, column: 16, scope: !31)
-// CHECK:STDOUT: !33 = !DILocation(line: 36, column: 1, scope: !31)
+// CHECK:STDOUT: !29 = !DILocation(line: 38, column: 16, scope: !26)
+// CHECK:STDOUT: !30 = !DILocation(line: 37, column: 1, scope: !26)
+// CHECK:STDOUT: !31 = distinct !DISubprogram(name: "G", linkageName: "_CG.Main.01a101e5421592ac", scope: null, file: !1, line: 37, type: !27, spFlags: DISPFlagDefinition, unit: !0)
+// CHECK:STDOUT: !32 = !DILocation(line: 38, column: 16, scope: !31)
+// CHECK:STDOUT: !33 = !DILocation(line: 37, column: 1, scope: !31)
 // CHECK:STDOUT:
diff --git a/toolchain/lower/testdata/function/generic/call_recursive_diamond.carbon b/toolchain/lower/testdata/function/generic/call_recursive_diamond.carbon
index a925f6407553..c77ecfe2e9e1 100644
--- a/toolchain/lower/testdata/function/generic/call_recursive_diamond.carbon
+++ b/toolchain/lower/testdata/function/generic/call_recursive_diamond.carbon
@@ -2,6 +2,7 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
+// EXTRA-ARGS: --include-carbon-core
 // INCLUDE-FILE: toolchain/testing/testdata/min_prelude/full.carbon
 //
 // AUTOUPDATE
@@ -77,14 +78,14 @@ fn M() {
 // CHECK:STDOUT:   store ptr %n.var, ptr %ptr_i32.var, align 8, !dbg !9
 // CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %ptr_f64.var), !dbg !10
 // CHECK:STDOUT:   store ptr %m.var, ptr %ptr_f64.var, align 8, !dbg !10
-// CHECK:STDOUT:   %.loc53_5 = load i32, ptr %n.var, align 4, !dbg !11
-// CHECK:STDOUT:   %A.call.loc53 = call i32 @_CA.Main.5bd8d5767580997a(i32 %.loc53_5, i32 0), !dbg !12
-// CHECK:STDOUT:   %.loc54_5 = load double, ptr %m.var, align 8, !dbg !13
-// CHECK:STDOUT:   %A.call.loc54 = call double @_CA.Main.c27b765f2159c9a0(double %.loc54_5, i32 0), !dbg !14
-// CHECK:STDOUT:   %.loc55_5 = load ptr, ptr %ptr_i32.var, align 8, !dbg !15
-// CHECK:STDOUT:   %A.call.loc55 = call ptr @_CA.Main.2621742a01881e29(ptr %.loc55_5, i32 0), !dbg !16
-// CHECK:STDOUT:   %.loc56_5 = load ptr, ptr %ptr_f64.var, align 8, !dbg !17
-// CHECK:STDOUT:   %A.call.loc56 = call ptr @_CA.Main.2621742a01881e29(ptr %.loc56_5, i32 0), !dbg !18
+// CHECK:STDOUT:   %.loc54_5 = load i32, ptr %n.var, align 4, !dbg !11
+// CHECK:STDOUT:   %A.call.loc54 = call i32 @_CA.Main.5bd8d5767580997a(i32 %.loc54_5, i32 0), !dbg !12
+// CHECK:STDOUT:   %.loc55_5 = load double, ptr %m.var, align 8, !dbg !13
+// CHECK:STDOUT:   %A.call.loc55 = call double @_CA.Main.c27b765f2159c9a0(double %.loc55_5, i32 0), !dbg !14
+// CHECK:STDOUT:   %.loc56_5 = load ptr, ptr %ptr_i32.var, align 8, !dbg !15
+// CHECK:STDOUT:   %A.call.loc56 = call ptr @_CA.Main.2621742a01881e29(ptr %.loc56_5, i32 0), !dbg !16
+// CHECK:STDOUT:   %.loc57_5 = load ptr, ptr %ptr_f64.var, align 8, !dbg !17
+// CHECK:STDOUT:   %A.call.loc57 = call ptr @_CA.Main.2621742a01881e29(ptr %.loc57_5, i32 0), !dbg !18
 // CHECK:STDOUT:   call void @"_COp.30d8007fdcc57f83:core.Destroy.Core"(ptr %m.var), !dbg !8
 // CHECK:STDOUT:   call void @"_COp.5e27612b9dd31a14:core.Destroy.Core"(ptr %n.var), !dbg !7
 // CHECK:STDOUT:   ret void, !dbg !19
@@ -109,21 +110,21 @@ fn M() {
 // CHECK:STDOUT: define linkonce_odr i32 @_CA.Main.5bd8d5767580997a(i32 %x, i32 %count) #0 !dbg !34 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Int.as.OrderedWith.impl.Greater.call = icmp sgt i32 %count, 4, !dbg !40
-// CHECK:STDOUT:   br i1 %Int.as.OrderedWith.impl.Greater.call, label %if.then.loc22, label %if.else.loc22, !dbg !41
+// CHECK:STDOUT:   br i1 %Int.as.OrderedWith.impl.Greater.call, label %if.then.loc23, label %if.else.loc23, !dbg !41
 // CHECK:STDOUT:
-// CHECK:STDOUT: if.then.loc22:                                    ; preds = %entry
+// CHECK:STDOUT: if.then.loc23:                                    ; preds = %entry
 // CHECK:STDOUT:   ret i32 %x, !dbg !42
 // CHECK:STDOUT:
-// CHECK:STDOUT: if.else.loc22:                                    ; preds = %entry
+// CHECK:STDOUT: if.else.loc23:                                    ; preds = %entry
 // CHECK:STDOUT:   %Int.as.ModWith.impl.Op.call = srem i32 %count, 2, !dbg !43
 // CHECK:STDOUT:   %Int.as.EqWith.impl.Equal.call = icmp eq i32 %Int.as.ModWith.impl.Op.call, 0, !dbg !43
-// CHECK:STDOUT:   br i1 %Int.as.EqWith.impl.Equal.call, label %if.then.loc25, label %if.else.loc25, !dbg !44
+// CHECK:STDOUT:   br i1 %Int.as.EqWith.impl.Equal.call, label %if.then.loc26, label %if.else.loc26, !dbg !44
 // CHECK:STDOUT:
-// CHECK:STDOUT: if.then.loc25:                                    ; preds = %if.else.loc22
+// CHECK:STDOUT: if.then.loc26:                                    ; preds = %if.else.loc23
 // CHECK:STDOUT:   %B.call = call i32 @_CB.Main.5bd8d5767580997a(i32 %x, i32 %count), !dbg !45
 // CHECK:STDOUT:   ret i32 %B.call, !dbg !46
 // CHECK:STDOUT:
-// CHECK:STDOUT: if.else.loc25:                                    ; preds = %if.else.loc22
+// CHECK:STDOUT: if.else.loc26:                                    ; preds = %if.else.loc23
 // CHECK:STDOUT:   %C.call = call i32 @_CC.Main.5bd8d5767580997a(i32 %x, i32 %count), !dbg !47
 // CHECK:STDOUT:   ret i32 %C.call, !dbg !48
 // CHECK:STDOUT: }
@@ -132,21 +133,21 @@ fn M() {
 // CHECK:STDOUT: define linkonce_odr double @_CA.Main.c27b765f2159c9a0(double %x, i32 %count) #0 !dbg !49 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Int.as.OrderedWith.impl.Greater.call = icmp sgt i32 %count, 4, !dbg !55
-// CHECK:STDOUT:   br i1 %Int.as.OrderedWith.impl.Greater.call, label %if.then.loc22, label %if.else.loc22, !dbg !56
+// CHECK:STDOUT:   br i1 %Int.as.OrderedWith.impl.Greater.call, label %if.then.loc23, label %if.else.loc23, !dbg !56
 // CHECK:STDOUT:
-// CHECK:STDOUT: if.then.loc22:                                    ; preds = %entry
+// CHECK:STDOUT: if.then.loc23:                                    ; preds = %entry
 // CHECK:STDOUT:   ret double %x, !dbg !57
 // CHECK:STDOUT:
-// CHECK:STDOUT: if.else.loc22:                                    ; preds = %entry
+// CHECK:STDOUT: if.else.loc23:                                    ; preds = %entry
 // CHECK:STDOUT:   %Int.as.ModWith.impl.Op.call = srem i32 %count, 2, !dbg !58
 // CHECK:STDOUT:   %Int.as.EqWith.impl.Equal.call = icmp eq i32 %Int.as.ModWith.impl.Op.call, 0, !dbg !58
-// CHECK:STDOUT:   br i1 %Int.as.EqWith.impl.Equal.call, label %if.then.loc25, label %if.else.loc25, !dbg !59
+// CHECK:STDOUT:   br i1 %Int.as.EqWith.impl.Equal.call, label %if.then.loc26, label %if.else.loc26, !dbg !59
 // CHECK:STDOUT:
-// CHECK:STDOUT: if.then.loc25:                                    ; preds = %if.else.loc22
+// CHECK:STDOUT: if.then.loc26:                                    ; preds = %if.else.loc23
 // CHECK:STDOUT:   %B.call = call double @_CB.Main.c27b765f2159c9a0(double %x, i32 %count), !dbg !60
 // CHECK:STDOUT:   ret double %B.call, !dbg !61
 // CHECK:STDOUT:
-// CHECK:STDOUT: if.else.loc25:                                    ; preds = %if.else.loc22
+// CHECK:STDOUT: if.else.loc26:                                    ; preds = %if.else.loc23
 // CHECK:STDOUT:   %C.call = call double @_CC.Main.c27b765f2159c9a0(double %x, i32 %count), !dbg !62
 // CHECK:STDOUT:   ret double %C.call, !dbg !63
 // CHECK:STDOUT: }
@@ -155,21 +156,21 @@ fn M() {
 // CHECK:STDOUT: define linkonce_odr ptr @_CA.Main.2621742a01881e29(ptr %x, i32 %count) #0 !dbg !64 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Int.as.OrderedWith.impl.Greater.call = icmp sgt i32 %count, 4, !dbg !68
-// CHECK:STDOUT:   br i1 %Int.as.OrderedWith.impl.Greater.call, label %if.then.loc22, label %if.else.loc22, !dbg !69
+// CHECK:STDOUT:   br i1 %Int.as.OrderedWith.impl.Greater.call, label %if.then.loc23, label %if.else.loc23, !dbg !69
 // CHECK:STDOUT:
-// CHECK:STDOUT: if.then.loc22:                                    ; preds = %entry
+// CHECK:STDOUT: if.then.loc23:                                    ; preds = %entry
 // CHECK:STDOUT:   ret ptr %x, !dbg !70
 // CHECK:STDOUT:
-// CHECK:STDOUT: if.else.loc22:                                    ; preds = %entry
+// CHECK:STDOUT: if.else.loc23:                                    ; preds = %entry
 // CHECK:STDOUT:   %Int.as.ModWith.impl.Op.call = srem i32 %count, 2, !dbg !71
 // CHECK:STDOUT:   %Int.as.EqWith.impl.Equal.call = icmp eq i32 %Int.as.ModWith.impl.Op.call, 0, !dbg !71
-// CHECK:STDOUT:   br i1 %Int.as.EqWith.impl.Equal.call, label %if.then.loc25, label %if.else.loc25, !dbg !72
+// CHECK:STDOUT:   br i1 %Int.as.EqWith.impl.Equal.call, label %if.then.loc26, label %if.else.loc26, !dbg !72
 // CHECK:STDOUT:
-// CHECK:STDOUT: if.then.loc25:                                    ; preds = %if.else.loc22
+// CHECK:STDOUT: if.then.loc26:                                    ; preds = %if.else.loc23
 // CHECK:STDOUT:   %B.call = call ptr @_CB.Main.2621742a01881e29(ptr %x, i32 %count), !dbg !73
 // CHECK:STDOUT:   ret ptr %B.call, !dbg !74
 // CHECK:STDOUT:
-// CHECK:STDOUT: if.else.loc25:                                    ; preds = %if.else.loc22
+// CHECK:STDOUT: if.else.loc26:                                    ; preds = %if.else.loc23
 // CHECK:STDOUT:   %C.call = call ptr @_CC.Main.2621742a01881e29(ptr %x, i32 %count), !dbg !75
 // CHECK:STDOUT:   ret ptr %C.call, !dbg !76
 // CHECK:STDOUT: }
@@ -266,140 +267,140 @@ fn M() {
 // CHECK:STDOUT: !1 = !DIFile(filename: "call_recursive_diamond.carbon", directory: "")
 // CHECK:STDOUT: !2 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !3 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !4 = distinct !DISubprogram(name: "M", linkageName: "_CM.Main", scope: null, file: !1, line: 47, type: !5, spFlags: DISPFlagDefinition, unit: !0)
+// CHECK:STDOUT: !4 = distinct !DISubprogram(name: "M", linkageName: "_CM.Main", scope: null, file: !1, line: 48, type: !5, spFlags: DISPFlagDefinition, unit: !0)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)
 // CHECK:STDOUT: !6 = !{null}
-// CHECK:STDOUT: !7 = !DILocation(line: 48, column: 3, scope: !4)
-// CHECK:STDOUT: !8 = !DILocation(line: 49, column: 3, scope: !4)
-// CHECK:STDOUT: !9 = !DILocation(line: 50, column: 3, scope: !4)
-// CHECK:STDOUT: !10 = !DILocation(line: 51, column: 3, scope: !4)
-// CHECK:STDOUT: !11 = !DILocation(line: 53, column: 5, scope: !4)
-// CHECK:STDOUT: !12 = !DILocation(line: 53, column: 3, scope: !4)
-// CHECK:STDOUT: !13 = !DILocation(line: 54, column: 5, scope: !4)
-// CHECK:STDOUT: !14 = !DILocation(line: 54, column: 3, scope: !4)
-// CHECK:STDOUT: !15 = !DILocation(line: 55, column: 5, scope: !4)
-// CHECK:STDOUT: !16 = !DILocation(line: 55, column: 3, scope: !4)
-// CHECK:STDOUT: !17 = !DILocation(line: 56, column: 5, scope: !4)
-// CHECK:STDOUT: !18 = !DILocation(line: 56, column: 3, scope: !4)
-// CHECK:STDOUT: !19 = !DILocation(line: 47, column: 1, scope: !4)
-// CHECK:STDOUT: !20 = distinct !DISubprogram(name: "Op", linkageName: "_COp.30d8007fdcc57f83:core.Destroy.Core", scope: null, file: !1, line: 49, type: !21, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !24)
+// CHECK:STDOUT: !7 = !DILocation(line: 49, column: 3, scope: !4)
+// CHECK:STDOUT: !8 = !DILocation(line: 50, column: 3, scope: !4)
+// CHECK:STDOUT: !9 = !DILocation(line: 51, column: 3, scope: !4)
+// CHECK:STDOUT: !10 = !DILocation(line: 52, column: 3, scope: !4)
+// CHECK:STDOUT: !11 = !DILocation(line: 54, column: 5, scope: !4)
+// CHECK:STDOUT: !12 = !DILocation(line: 54, column: 3, scope: !4)
+// CHECK:STDOUT: !13 = !DILocation(line: 55, column: 5, scope: !4)
+// CHECK:STDOUT: !14 = !DILocation(line: 55, column: 3, scope: !4)
+// CHECK:STDOUT: !15 = !DILocation(line: 56, column: 5, scope: !4)
+// CHECK:STDOUT: !16 = !DILocation(line: 56, column: 3, scope: !4)
+// CHECK:STDOUT: !17 = !DILocation(line: 57, column: 5, scope: !4)
+// CHECK:STDOUT: !18 = !DILocation(line: 57, column: 3, scope: !4)
+// CHECK:STDOUT: !19 = !DILocation(line: 48, column: 1, scope: !4)
+// CHECK:STDOUT: !20 = distinct !DISubprogram(name: "Op", linkageName: "_COp.30d8007fdcc57f83:core.Destroy.Core", scope: null, file: !1, line: 50, type: !21, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !24)
 // CHECK:STDOUT: !21 = !DISubroutineType(types: !22)
 // CHECK:STDOUT: !22 = !{null, !23}
 // CHECK:STDOUT: !23 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: null, size: 64)
 // CHECK:STDOUT: !24 = !{!25}
 // CHECK:STDOUT: !25 = !DILocalVariable(arg: 1, scope: !20, type: !23)
-// CHECK:STDOUT: !26 = !DILocation(line: 49, column: 3, scope: !20)
-// CHECK:STDOUT: !27 = distinct !DISubprogram(name: "Op", linkageName: "_COp.5e27612b9dd31a14:core.Destroy.Core", scope: null, file: !1, line: 48, type: !28, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !31)
+// CHECK:STDOUT: !26 = !DILocation(line: 50, column: 3, scope: !20)
+// CHECK:STDOUT: !27 = distinct !DISubprogram(name: "Op", linkageName: "_COp.5e27612b9dd31a14:core.Destroy.Core", scope: null, file: !1, line: 49, type: !28, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !31)
 // CHECK:STDOUT: !28 = !DISubroutineType(types: !29)
 // CHECK:STDOUT: !29 = !{null, !30}
 // CHECK:STDOUT: !30 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
 // CHECK:STDOUT: !31 = !{!32}
 // CHECK:STDOUT: !32 = !DILocalVariable(arg: 1, scope: !27, type: !30)
-// CHECK:STDOUT: !33 = !DILocation(line: 48, column: 3, scope: !27)
-// CHECK:STDOUT: !34 = distinct !DISubprogram(name: "A", linkageName: "_CA.Main.5bd8d5767580997a", scope: null, file: !1, line: 21, type: !35, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !37)
+// CHECK:STDOUT: !33 = !DILocation(line: 49, column: 3, scope: !27)
+// CHECK:STDOUT: !34 = distinct !DISubprogram(name: "A", linkageName: "_CA.Main.5bd8d5767580997a", scope: null, file: !1, line: 22, type: !35, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !37)
 // CHECK:STDOUT: !35 = !DISubroutineType(types: !36)
 // CHECK:STDOUT: !36 = !{!30, !30, !30}
 // CHECK:STDOUT: !37 = !{!38, !39}
 // CHECK:STDOUT: !38 = !DILocalVariable(arg: 1, scope: !34, type: !30)
 // CHECK:STDOUT: !39 = !DILocalVariable(arg: 2, scope: !34, type: !30)
-// CHECK:STDOUT: !40 = !DILocation(line: 22, column: 7, scope: !34)
-// CHECK:STDOUT: !41 = !DILocation(line: 22, column: 6, scope: !34)
-// CHECK:STDOUT: !42 = !DILocation(line: 23, column: 5, scope: !34)
-// CHECK:STDOUT: !43 = !DILocation(line: 25, column: 7, scope: !34)
-// CHECK:STDOUT: !44 = !DILocation(line: 25, column: 6, scope: !34)
-// CHECK:STDOUT: !45 = !DILocation(line: 26, column: 12, scope: !34)
-// CHECK:STDOUT: !46 = !DILocation(line: 26, column: 5, scope: !34)
-// CHECK:STDOUT: !47 = !DILocation(line: 28, column: 12, scope: !34)
-// CHECK:STDOUT: !48 = !DILocation(line: 28, column: 5, scope: !34)
-// CHECK:STDOUT: !49 = distinct !DISubprogram(name: "A", linkageName: "_CA.Main.c27b765f2159c9a0", scope: null, file: !1, line: 21, type: !50, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !52)
+// CHECK:STDOUT: !40 = !DILocation(line: 23, column: 7, scope: !34)
+// CHECK:STDOUT: !41 = !DILocation(line: 23, column: 6, scope: !34)
+// CHECK:STDOUT: !42 = !DILocation(line: 24, column: 5, scope: !34)
+// CHECK:STDOUT: !43 = !DILocation(line: 26, column: 7, scope: !34)
+// CHECK:STDOUT: !44 = !DILocation(line: 26, column: 6, scope: !34)
+// CHECK:STDOUT: !45 = !DILocation(line: 27, column: 12, scope: !34)
+// CHECK:STDOUT: !46 = !DILocation(line: 27, column: 5, scope: !34)
+// CHECK:STDOUT: !47 = !DILocation(line: 29, column: 12, scope: !34)
+// CHECK:STDOUT: !48 = !DILocation(line: 29, column: 5, scope: !34)
+// CHECK:STDOUT: !49 = distinct !DISubprogram(name: "A", linkageName: "_CA.Main.c27b765f2159c9a0", scope: null, file: !1, line: 22, type: !50, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !52)
 // CHECK:STDOUT: !50 = !DISubroutineType(types: !51)
 // CHECK:STDOUT: !51 = !{!23, !23, !30}
 // CHECK:STDOUT: !52 = !{!53, !54}
 // CHECK:STDOUT: !53 = !DILocalVariable(arg: 1, scope: !49, type: !23)
 // CHECK:STDOUT: !54 = !DILocalVariable(arg: 2, scope: !49, type: !30)
-// CHECK:STDOUT: !55 = !DILocation(line: 22, column: 7, scope: !49)
-// CHECK:STDOUT: !56 = !DILocation(line: 22, column: 6, scope: !49)
-// CHECK:STDOUT: !57 = !DILocation(line: 23, column: 5, scope: !49)
-// CHECK:STDOUT: !58 = !DILocation(line: 25, column: 7, scope: !49)
-// CHECK:STDOUT: !59 = !DILocation(line: 25, column: 6, scope: !49)
-// CHECK:STDOUT: !60 = !DILocation(line: 26, column: 12, scope: !49)
-// CHECK:STDOUT: !61 = !DILocation(line: 26, column: 5, scope: !49)
-// CHECK:STDOUT: !62 = !DILocation(line: 28, column: 12, scope: !49)
-// CHECK:STDOUT: !63 = !DILocation(line: 28, column: 5, scope: !49)
-// CHECK:STDOUT: !64 = distinct !DISubprogram(name: "A", linkageName: "_CA.Main.2621742a01881e29", scope: null, file: !1, line: 21, type: !50, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !65)
+// CHECK:STDOUT: !55 = !DILocation(line: 23, column: 7, scope: !49)
+// CHECK:STDOUT: !56 = !DILocation(line: 23, column: 6, scope: !49)
+// CHECK:STDOUT: !57 = !DILocation(line: 24, column: 5, scope: !49)
+// CHECK:STDOUT: !58 = !DILocation(line: 26, column: 7, scope: !49)
+// CHECK:STDOUT: !59 = !DILocation(line: 26, column: 6, scope: !49)
+// CHECK:STDOUT: !60 = !DILocation(line: 27, column: 12, scope: !49)
+// CHECK:STDOUT: !61 = !DILocation(line: 27, column: 5, scope: !49)
+// CHECK:STDOUT: !62 = !DILocation(line: 29, column: 12, scope: !49)
+// CHECK:STDOUT: !63 = !DILocation(line: 29, column: 5, scope: !49)
+// CHECK:STDOUT: !64 = distinct !DISubprogram(name: "A", linkageName: "_CA.Main.2621742a01881e29", scope: null, file: !1, line: 22, type: !50, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !65)
 // CHECK:STDOUT: !65 = !{!66, !67}
 // CHECK:STDOUT: !66 = !DILocalVariable(arg: 1, scope: !64, type: !23)
 // CHECK:STDOUT: !67 = !DILocalVariable(arg: 2, scope: !64, type: !30)
-// CHECK:STDOUT: !68 = !DILocation(line: 22, column: 7, scope: !64)
-// CHECK:STDOUT: !69 = !DILocation(line: 22, column: 6, scope: !64)
-// CHECK:STDOUT: !70 = !DILocation(line: 23, column: 5, scope: !64)
-// CHECK:STDOUT: !71 = !DILocation(line: 25, column: 7, scope: !64)
-// CHECK:STDOUT: !72 = !DILocation(line: 25, column: 6, scope: !64)
-// CHECK:STDOUT: !73 = !DILocation(line: 26, column: 12, scope: !64)
-// CHECK:STDOUT: !74 = !DILocation(line: 26, column: 5, scope: !64)
-// CHECK:STDOUT: !75 = !DILocation(line: 28, column: 12, scope: !64)
-// CHECK:STDOUT: !76 = !DILocation(line: 28, column: 5, scope: !64)
-// CHECK:STDOUT: !77 = distinct !DISubprogram(name: "B", linkageName: "_CB.Main.5bd8d5767580997a", scope: null, file: !1, line: 33, type: !35, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !78)
+// CHECK:STDOUT: !68 = !DILocation(line: 23, column: 7, scope: !64)
+// CHECK:STDOUT: !69 = !DILocation(line: 23, column: 6, scope: !64)
+// CHECK:STDOUT: !70 = !DILocation(line: 24, column: 5, scope: !64)
+// CHECK:STDOUT: !71 = !DILocation(line: 26, column: 7, scope: !64)
+// CHECK:STDOUT: !72 = !DILocation(line: 26, column: 6, scope: !64)
+// CHECK:STDOUT: !73 = !DILocation(line: 27, column: 12, scope: !64)
+// CHECK:STDOUT: !74 = !DILocation(line: 27, column: 5, scope: !64)
+// CHECK:STDOUT: !75 = !DILocation(line: 29, column: 12, scope: !64)
+// CHECK:STDOUT: !76 = !DILocation(line: 29, column: 5, scope: !64)
+// CHECK:STDOUT: !77 = distinct !DISubprogram(name: "B", linkageName: "_CB.Main.5bd8d5767580997a", scope: null, file: !1, line: 34, type: !35, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !78)
 // CHECK:STDOUT: !78 = !{!79, !80}
 // CHECK:STDOUT: !79 = !DILocalVariable(arg: 1, scope: !77, type: !30)
 // CHECK:STDOUT: !80 = !DILocalVariable(arg: 2, scope: !77, type: !30)
-// CHECK:STDOUT: !81 = !DILocation(line: 34, column: 3, scope: !77)
-// CHECK:STDOUT: !82 = !DILocation(line: 35, column: 10, scope: !77)
-// CHECK:STDOUT: !83 = !DILocation(line: 35, column: 3, scope: !77)
-// CHECK:STDOUT: !84 = distinct !DISubprogram(name: "C", linkageName: "_CC.Main.5bd8d5767580997a", scope: null, file: !1, line: 38, type: !35, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !85)
+// CHECK:STDOUT: !81 = !DILocation(line: 35, column: 3, scope: !77)
+// CHECK:STDOUT: !82 = !DILocation(line: 36, column: 10, scope: !77)
+// CHECK:STDOUT: !83 = !DILocation(line: 36, column: 3, scope: !77)
+// CHECK:STDOUT: !84 = distinct !DISubprogram(name: "C", linkageName: "_CC.Main.5bd8d5767580997a", scope: null, file: !1, line: 39, type: !35, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !85)
 // CHECK:STDOUT: !85 = !{!86, !87}
 // CHECK:STDOUT: !86 = !DILocalVariable(arg: 1, scope: !84, type: !30)
 // CHECK:STDOUT: !87 = !DILocalVariable(arg: 2, scope: !84, type: !30)
-// CHECK:STDOUT: !88 = !DILocation(line: 39, column: 3, scope: !84)
-// CHECK:STDOUT: !89 = !DILocation(line: 40, column: 10, scope: !84)
-// CHECK:STDOUT: !90 = !DILocation(line: 40, column: 3, scope: !84)
-// CHECK:STDOUT: !91 = distinct !DISubprogram(name: "B", linkageName: "_CB.Main.c27b765f2159c9a0", scope: null, file: !1, line: 33, type: !50, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !92)
+// CHECK:STDOUT: !88 = !DILocation(line: 40, column: 3, scope: !84)
+// CHECK:STDOUT: !89 = !DILocation(line: 41, column: 10, scope: !84)
+// CHECK:STDOUT: !90 = !DILocation(line: 41, column: 3, scope: !84)
+// CHECK:STDOUT: !91 = distinct !DISubprogram(name: "B", linkageName: "_CB.Main.c27b765f2159c9a0", scope: null, file: !1, line: 34, type: !50, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !92)
 // CHECK:STDOUT: !92 = !{!93, !94}
 // CHECK:STDOUT: !93 = !DILocalVariable(arg: 1, scope: !91, type: !23)
 // CHECK:STDOUT: !94 = !DILocalVariable(arg: 2, scope: !91, type: !30)
-// CHECK:STDOUT: !95 = !DILocation(line: 34, column: 3, scope: !91)
-// CHECK:STDOUT: !96 = !DILocation(line: 35, column: 10, scope: !91)
-// CHECK:STDOUT: !97 = !DILocation(line: 35, column: 3, scope: !91)
-// CHECK:STDOUT: !98 = distinct !DISubprogram(name: "C", linkageName: "_CC.Main.c27b765f2159c9a0", scope: null, file: !1, line: 38, type: !50, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !99)
+// CHECK:STDOUT: !95 = !DILocation(line: 35, column: 3, scope: !91)
+// CHECK:STDOUT: !96 = !DILocation(line: 36, column: 10, scope: !91)
+// CHECK:STDOUT: !97 = !DILocation(line: 36, column: 3, scope: !91)
+// CHECK:STDOUT: !98 = distinct !DISubprogram(name: "C", linkageName: "_CC.Main.c27b765f2159c9a0", scope: null, file: !1, line: 39, type: !50, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !99)
 // CHECK:STDOUT: !99 = !{!100, !101}
 // CHECK:STDOUT: !100 = !DILocalVariable(arg: 1, scope: !98, type: !23)
 // CHECK:STDOUT: !101 = !DILocalVariable(arg: 2, scope: !98, type: !30)
-// CHECK:STDOUT: !102 = !DILocation(line: 39, column: 3, scope: !98)
-// CHECK:STDOUT: !103 = !DILocation(line: 40, column: 10, scope: !98)
-// CHECK:STDOUT: !104 = !DILocation(line: 40, column: 3, scope: !98)
-// CHECK:STDOUT: !105 = distinct !DISubprogram(name: "B", linkageName: "_CB.Main.2621742a01881e29", scope: null, file: !1, line: 33, type: !50, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !106)
+// CHECK:STDOUT: !102 = !DILocation(line: 40, column: 3, scope: !98)
+// CHECK:STDOUT: !103 = !DILocation(line: 41, column: 10, scope: !98)
+// CHECK:STDOUT: !104 = !DILocation(line: 41, column: 3, scope: !98)
+// CHECK:STDOUT: !105 = distinct !DISubprogram(name: "B", linkageName: "_CB.Main.2621742a01881e29", scope: null, file: !1, line: 34, type: !50, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !106)
 // CHECK:STDOUT: !106 = !{!107, !108}
 // CHECK:STDOUT: !107 = !DILocalVariable(arg: 1, scope: !105, type: !23)
 // CHECK:STDOUT: !108 = !DILocalVariable(arg: 2, scope: !105, type: !30)
-// CHECK:STDOUT: !109 = !DILocation(line: 34, column: 3, scope: !105)
-// CHECK:STDOUT: !110 = !DILocation(line: 35, column: 10, scope: !105)
-// CHECK:STDOUT: !111 = !DILocation(line: 35, column: 3, scope: !105)
-// CHECK:STDOUT: !112 = distinct !DISubprogram(name: "C", linkageName: "_CC.Main.2621742a01881e29", scope: null, file: !1, line: 38, type: !50, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !113)
+// CHECK:STDOUT: !109 = !DILocation(line: 35, column: 3, scope: !105)
+// CHECK:STDOUT: !110 = !DILocation(line: 36, column: 10, scope: !105)
+// CHECK:STDOUT: !111 = !DILocation(line: 36, column: 3, scope: !105)
+// CHECK:STDOUT: !112 = distinct !DISubprogram(name: "C", linkageName: "_CC.Main.2621742a01881e29", scope: null, file: !1, line: 39, type: !50, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !113)
 // CHECK:STDOUT: !113 = !{!114, !115}
 // CHECK:STDOUT: !114 = !DILocalVariable(arg: 1, scope: !112, type: !23)
 // CHECK:STDOUT: !115 = !DILocalVariable(arg: 2, scope: !112, type: !30)
-// CHECK:STDOUT: !116 = !DILocation(line: 39, column: 3, scope: !112)
-// CHECK:STDOUT: !117 = !DILocation(line: 40, column: 10, scope: !112)
-// CHECK:STDOUT: !118 = !DILocation(line: 40, column: 3, scope: !112)
-// CHECK:STDOUT: !119 = distinct !DISubprogram(name: "D", linkageName: "_CD.Main.5bd8d5767580997a", scope: null, file: !1, line: 43, type: !35, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !120)
+// CHECK:STDOUT: !116 = !DILocation(line: 40, column: 3, scope: !112)
+// CHECK:STDOUT: !117 = !DILocation(line: 41, column: 10, scope: !112)
+// CHECK:STDOUT: !118 = !DILocation(line: 41, column: 3, scope: !112)
+// CHECK:STDOUT: !119 = distinct !DISubprogram(name: "D", linkageName: "_CD.Main.5bd8d5767580997a", scope: null, file: !1, line: 44, type: !35, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !120)
 // CHECK:STDOUT: !120 = !{!121, !122}
 // CHECK:STDOUT: !121 = !DILocalVariable(arg: 1, scope: !119, type: !30)
 // CHECK:STDOUT: !122 = !DILocalVariable(arg: 2, scope: !119, type: !30)
-// CHECK:STDOUT: !123 = !DILocation(line: 44, column: 15, scope: !119)
-// CHECK:STDOUT: !124 = !DILocation(line: 44, column: 10, scope: !119)
-// CHECK:STDOUT: !125 = !DILocation(line: 44, column: 3, scope: !119)
-// CHECK:STDOUT: !126 = distinct !DISubprogram(name: "D", linkageName: "_CD.Main.c27b765f2159c9a0", scope: null, file: !1, line: 43, type: !50, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !127)
+// CHECK:STDOUT: !123 = !DILocation(line: 45, column: 15, scope: !119)
+// CHECK:STDOUT: !124 = !DILocation(line: 45, column: 10, scope: !119)
+// CHECK:STDOUT: !125 = !DILocation(line: 45, column: 3, scope: !119)
+// CHECK:STDOUT: !126 = distinct !DISubprogram(name: "D", linkageName: "_CD.Main.c27b765f2159c9a0", scope: null, file: !1, line: 44, type: !50, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !127)
 // CHECK:STDOUT: !127 = !{!128, !129}
 // CHECK:STDOUT: !128 = !DILocalVariable(arg: 1, scope: !126, type: !23)
 // CHECK:STDOUT: !129 = !DILocalVariable(arg: 2, scope: !126, type: !30)
-// CHECK:STDOUT: !130 = !DILocation(line: 44, column: 15, scope: !126)
-// CHECK:STDOUT: !131 = !DILocation(line: 44, column: 10, scope: !126)
-// CHECK:STDOUT: !132 = !DILocation(line: 44, column: 3, scope: !126)
-// CHECK:STDOUT: !133 = distinct !DISubprogram(name: "D", linkageName: "_CD.Main.2621742a01881e29", scope: null, file: !1, line: 43, type: !50, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !134)
+// CHECK:STDOUT: !130 = !DILocation(line: 45, column: 15, scope: !126)
+// CHECK:STDOUT: !131 = !DILocation(line: 45, column: 10, scope: !126)
+// CHECK:STDOUT: !132 = !DILocation(line: 45, column: 3, scope: !126)
+// CHECK:STDOUT: !133 = distinct !DISubprogram(name: "D", linkageName: "_CD.Main.2621742a01881e29", scope: null, file: !1, line: 44, type: !50, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !134)
 // CHECK:STDOUT: !134 = !{!135, !136}
 // CHECK:STDOUT: !135 = !DILocalVariable(arg: 1, scope: !133, type: !23)
 // CHECK:STDOUT: !136 = !DILocalVariable(arg: 2, scope: !133, type: !30)
-// CHECK:STDOUT: !137 = !DILocation(line: 44, column: 15, scope: !133)
-// CHECK:STDOUT: !138 = !DILocation(line: 44, column: 10, scope: !133)
-// CHECK:STDOUT: !139 = !DILocation(line: 44, column: 3, scope: !133)
+// CHECK:STDOUT: !137 = !DILocation(line: 45, column: 15, scope: !133)
+// CHECK:STDOUT: !138 = !DILocation(line: 45, column: 10, scope: !133)
+// CHECK:STDOUT: !139 = !DILocation(line: 45, column: 3, scope: !133)
 // CHECK:STDOUT:
diff --git a/toolchain/lower/testdata/function/generic/call_recursive_impl.carbon b/toolchain/lower/testdata/function/generic/call_recursive_impl.carbon
index d3d781e9af7e..02de8402ef00 100644
--- a/toolchain/lower/testdata/function/generic/call_recursive_impl.carbon
+++ b/toolchain/lower/testdata/function/generic/call_recursive_impl.carbon
@@ -2,6 +2,7 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
+// EXTRA-ARGS: --include-carbon-core
 // INCLUDE-FILE: toolchain/testing/testdata/min_prelude/full.carbon
 //
 // AUTOUPDATE
@@ -64,8 +65,8 @@ fn Run() {
 // CHECK:STDOUT: ; Function Attrs: nounwind
 // CHECK:STDOUT: define i32 @main() #0 !dbg !12 {
 // CHECK:STDOUT: entry:
-// CHECK:STDOUT:   %G.call.loc40 = call i32 @_CG.Main.c81631f865470482(i32 0), !dbg !16
-// CHECK:STDOUT:   %G.call.loc41 = call i32 @_CG.Main.0b241ec84a68877b(i32 0), !dbg !17
+// CHECK:STDOUT:   %G.call.loc41 = call i32 @_CG.Main.c81631f865470482(i32 0), !dbg !16
+// CHECK:STDOUT:   %G.call.loc42 = call i32 @_CG.Main.0b241ec84a68877b(i32 0), !dbg !17
 // CHECK:STDOUT:   ret i32 0, !dbg !18
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
@@ -115,41 +116,41 @@ fn Run() {
 // CHECK:STDOUT: !1 = !DIFile(filename: "call_recursive_impl.carbon", directory: "")
 // CHECK:STDOUT: !2 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !3 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !4 = distinct !DISubprogram(name: "F", linkageName: "_CF.X.Main:I.Main", scope: null, file: !1, line: 20, type: !5, spFlags: DISPFlagDefinition, unit: !0)
+// CHECK:STDOUT: !4 = distinct !DISubprogram(name: "F", linkageName: "_CF.X.Main:I.Main", scope: null, file: !1, line: 21, type: !5, spFlags: DISPFlagDefinition, unit: !0)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)
 // CHECK:STDOUT: !6 = !{null}
-// CHECK:STDOUT: !7 = !DILocation(line: 20, column: 12, scope: !4)
-// CHECK:STDOUT: !8 = !DILocation(line: 20, column: 3, scope: !4)
-// CHECK:STDOUT: !9 = distinct !DISubprogram(name: "F", linkageName: "_CF.Y.Main:I.Main", scope: null, file: !1, line: 24, type: !5, spFlags: DISPFlagDefinition, unit: !0)
-// CHECK:STDOUT: !10 = !DILocation(line: 24, column: 12, scope: !9)
-// CHECK:STDOUT: !11 = !DILocation(line: 24, column: 3, scope: !9)
-// CHECK:STDOUT: !12 = distinct !DISubprogram(name: "Run", linkageName: "main", scope: null, file: !1, line: 39, type: !13, spFlags: DISPFlagDefinition, unit: !0)
+// CHECK:STDOUT: !7 = !DILocation(line: 21, column: 12, scope: !4)
+// CHECK:STDOUT: !8 = !DILocation(line: 21, column: 3, scope: !4)
+// CHECK:STDOUT: !9 = distinct !DISubprogram(name: "F", linkageName: "_CF.Y.Main:I.Main", scope: null, file: !1, line: 25, type: !5, spFlags: DISPFlagDefinition, unit: !0)
+// CHECK:STDOUT: !10 = !DILocation(line: 25, column: 12, scope: !9)
+// CHECK:STDOUT: !11 = !DILocation(line: 25, column: 3, scope: !9)
+// CHECK:STDOUT: !12 = distinct !DISubprogram(name: "Run", linkageName: "main", scope: null, file: !1, line: 40, type: !13, spFlags: DISPFlagDefinition, unit: !0)
 // CHECK:STDOUT: !13 = !DISubroutineType(types: !14)
 // CHECK:STDOUT: !14 = !{!15}
 // CHECK:STDOUT: !15 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
-// CHECK:STDOUT: !16 = !DILocation(line: 40, column: 3, scope: !12)
-// CHECK:STDOUT: !17 = !DILocation(line: 41, column: 3, scope: !12)
-// CHECK:STDOUT: !18 = !DILocation(line: 39, column: 1, scope: !12)
-// CHECK:STDOUT: !19 = distinct !DISubprogram(name: "G", linkageName: "_CG.Main.c81631f865470482", scope: null, file: !1, line: 30, type: !20, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !22)
+// CHECK:STDOUT: !16 = !DILocation(line: 41, column: 3, scope: !12)
+// CHECK:STDOUT: !17 = !DILocation(line: 42, column: 3, scope: !12)
+// CHECK:STDOUT: !18 = !DILocation(line: 40, column: 1, scope: !12)
+// CHECK:STDOUT: !19 = distinct !DISubprogram(name: "G", linkageName: "_CG.Main.c81631f865470482", scope: null, file: !1, line: 31, type: !20, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !22)
 // CHECK:STDOUT: !20 = !DISubroutineType(types: !21)
 // CHECK:STDOUT: !21 = !{!15, !15}
 // CHECK:STDOUT: !22 = !{!23}
 // CHECK:STDOUT: !23 = !DILocalVariable(arg: 1, scope: !19, type: !15)
-// CHECK:STDOUT: !24 = !DILocation(line: 31, column: 3, scope: !19)
-// CHECK:STDOUT: !25 = !DILocation(line: 33, column: 7, scope: !19)
-// CHECK:STDOUT: !26 = !DILocation(line: 33, column: 6, scope: !19)
-// CHECK:STDOUT: !27 = !DILocation(line: 34, column: 5, scope: !19)
-// CHECK:STDOUT: !28 = !DILocation(line: 36, column: 15, scope: !19)
-// CHECK:STDOUT: !29 = !DILocation(line: 36, column: 10, scope: !19)
-// CHECK:STDOUT: !30 = !DILocation(line: 36, column: 3, scope: !19)
-// CHECK:STDOUT: !31 = distinct !DISubprogram(name: "G", linkageName: "_CG.Main.0b241ec84a68877b", scope: null, file: !1, line: 30, type: !20, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !32)
+// CHECK:STDOUT: !24 = !DILocation(line: 32, column: 3, scope: !19)
+// CHECK:STDOUT: !25 = !DILocation(line: 34, column: 7, scope: !19)
+// CHECK:STDOUT: !26 = !DILocation(line: 34, column: 6, scope: !19)
+// CHECK:STDOUT: !27 = !DILocation(line: 35, column: 5, scope: !19)
+// CHECK:STDOUT: !28 = !DILocation(line: 37, column: 15, scope: !19)
+// CHECK:STDOUT: !29 = !DILocation(line: 37, column: 10, scope: !19)
+// CHECK:STDOUT: !30 = !DILocation(line: 37, column: 3, scope: !19)
+// CHECK:STDOUT: !31 = distinct !DISubprogram(name: "G", linkageName: "_CG.Main.0b241ec84a68877b", scope: null, file: !1, line: 31, type: !20, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !32)
 // CHECK:STDOUT: !32 = !{!33}
 // CHECK:STDOUT: !33 = !DILocalVariable(arg: 1, scope: !31, type: !15)
-// CHECK:STDOUT: !34 = !DILocation(line: 31, column: 3, scope: !31)
-// CHECK:STDOUT: !35 = !DILocation(line: 33, column: 7, scope: !31)
-// CHECK:STDOUT: !36 = !DILocation(line: 33, column: 6, scope: !31)
-// CHECK:STDOUT: !37 = !DILocation(line: 34, column: 5, scope: !31)
-// CHECK:STDOUT: !38 = !DILocation(line: 36, column: 15, scope: !31)
-// CHECK:STDOUT: !39 = !DILocation(line: 36, column: 10, scope: !31)
-// CHECK:STDOUT: !40 = !DILocation(line: 36, column: 3, scope: !31)
+// CHECK:STDOUT: !34 = !DILocation(line: 32, column: 3, scope: !31)
+// CHECK:STDOUT: !35 = !DILocation(line: 34, column: 7, scope: !31)
+// CHECK:STDOUT: !36 = !DILocation(line: 34, column: 6, scope: !31)
+// CHECK:STDOUT: !37 = !DILocation(line: 35, column: 5, scope: !31)
+// CHECK:STDOUT: !38 = !DILocation(line: 37, column: 15, scope: !31)
+// CHECK:STDOUT: !39 = !DILocation(line: 37, column: 10, scope: !31)
+// CHECK:STDOUT: !40 = !DILocation(line: 37, column: 3, scope: !31)
 // CHECK:STDOUT:
diff --git a/toolchain/lower/testdata/function/generic/call_recursive_sccs_deep.carbon b/toolchain/lower/testdata/function/generic/call_recursive_sccs_deep.carbon
index 2996caa05eb9..1466f33635a0 100644
--- a/toolchain/lower/testdata/function/generic/call_recursive_sccs_deep.carbon
+++ b/toolchain/lower/testdata/function/generic/call_recursive_sccs_deep.carbon
@@ -2,6 +2,7 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
+// EXTRA-ARGS: --include-carbon-core
 // INCLUDE-FILE: toolchain/testing/testdata/min_prelude/full.carbon
 //
 // AUTOUPDATE
@@ -103,14 +104,14 @@ fn M() {
 // CHECK:STDOUT:   store ptr %n.var, ptr %ptr_i32.var, align 8, !dbg !9
 // CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %ptr_f64.var), !dbg !10
 // CHECK:STDOUT:   store ptr %m.var, ptr %ptr_f64.var, align 8, !dbg !10
-// CHECK:STDOUT:   %.loc79_5 = load i32, ptr %n.var, align 4, !dbg !11
-// CHECK:STDOUT:   %A.call.loc79 = call i32 @_CA.Main.5bd8d5767580997a(i32 %.loc79_5, i32 0), !dbg !12
-// CHECK:STDOUT:   %.loc80_5 = load double, ptr %m.var, align 8, !dbg !13
-// CHECK:STDOUT:   %A.call.loc80 = call double @_CA.Main.c27b765f2159c9a0(double %.loc80_5, i32 0), !dbg !14
-// CHECK:STDOUT:   %.loc81_5 = load ptr, ptr %ptr_i32.var, align 8, !dbg !15
-// CHECK:STDOUT:   %A.call.loc81 = call ptr @_CA.Main.2621742a01881e29(ptr %.loc81_5, i32 0), !dbg !16
-// CHECK:STDOUT:   %.loc82_5 = load ptr, ptr %ptr_f64.var, align 8, !dbg !17
-// CHECK:STDOUT:   %A.call.loc82 = call ptr @_CA.Main.2621742a01881e29(ptr %.loc82_5, i32 0), !dbg !18
+// CHECK:STDOUT:   %.loc80_5 = load i32, ptr %n.var, align 4, !dbg !11
+// CHECK:STDOUT:   %A.call.loc80 = call i32 @_CA.Main.5bd8d5767580997a(i32 %.loc80_5, i32 0), !dbg !12
+// CHECK:STDOUT:   %.loc81_5 = load double, ptr %m.var, align 8, !dbg !13
+// CHECK:STDOUT:   %A.call.loc81 = call double @_CA.Main.c27b765f2159c9a0(double %.loc81_5, i32 0), !dbg !14
+// CHECK:STDOUT:   %.loc82_5 = load ptr, ptr %ptr_i32.var, align 8, !dbg !15
+// CHECK:STDOUT:   %A.call.loc82 = call ptr @_CA.Main.2621742a01881e29(ptr %.loc82_5, i32 0), !dbg !16
+// CHECK:STDOUT:   %.loc83_5 = load ptr, ptr %ptr_f64.var, align 8, !dbg !17
+// CHECK:STDOUT:   %A.call.loc83 = call ptr @_CA.Main.2621742a01881e29(ptr %.loc83_5, i32 0), !dbg !18
 // CHECK:STDOUT:   call void @"_COp.30d8007fdcc57f83:core.Destroy.Core"(ptr %m.var), !dbg !8
 // CHECK:STDOUT:   call void @"_COp.5e27612b9dd31a14:core.Destroy.Core"(ptr %n.var), !dbg !7
 // CHECK:STDOUT:   ret void, !dbg !19
@@ -166,21 +167,21 @@ fn M() {
 // CHECK:STDOUT: define linkonce_odr i32 @_CD.Main.5bd8d5767580997a(i32 %x, i32 %count) #0 !dbg !67 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Int.as.OrderedWith.impl.Greater.call = icmp sgt i32 %count, 4, !dbg !71
-// CHECK:STDOUT:   br i1 %Int.as.OrderedWith.impl.Greater.call, label %if.then.loc48, label %if.else.loc48, !dbg !72
+// CHECK:STDOUT:   br i1 %Int.as.OrderedWith.impl.Greater.call, label %if.then.loc49, label %if.else.loc49, !dbg !72
 // CHECK:STDOUT:
-// CHECK:STDOUT: if.then.loc48:                                    ; preds = %entry
+// CHECK:STDOUT: if.then.loc49:                                    ; preds = %entry
 // CHECK:STDOUT:   ret i32 %x, !dbg !73
 // CHECK:STDOUT:
-// CHECK:STDOUT: if.else.loc48:                                    ; preds = %entry
+// CHECK:STDOUT: if.else.loc49:                                    ; preds = %entry
 // CHECK:STDOUT:   %Int.as.ModWith.impl.Op.call = srem i32 %count, 2, !dbg !74
 // CHECK:STDOUT:   %Int.as.EqWith.impl.Equal.call = icmp eq i32 %Int.as.ModWith.impl.Op.call, 0, !dbg !74
-// CHECK:STDOUT:   br i1 %Int.as.EqWith.impl.Equal.call, label %if.then.loc51, label %if.else.loc51, !dbg !75
+// CHECK:STDOUT:   br i1 %Int.as.EqWith.impl.Equal.call, label %if.then.loc52, label %if.else.loc52, !dbg !75
 // CHECK:STDOUT:
-// CHECK:STDOUT: if.then.loc51:                                    ; preds = %if.else.loc48
+// CHECK:STDOUT: if.then.loc52:                                    ; preds = %if.else.loc49
 // CHECK:STDOUT:   %E.call = call i32 @_CE.Main.5bd8d5767580997a(i32 %x, i32 %count), !dbg !76
 // CHECK:STDOUT:   ret i32 %E.call, !dbg !77
 // CHECK:STDOUT:
-// CHECK:STDOUT: if.else.loc51:                                    ; preds = %if.else.loc48
+// CHECK:STDOUT: if.else.loc52:                                    ; preds = %if.else.loc49
 // CHECK:STDOUT:   %F.call = call i32 @_CF.Main.5bd8d5767580997a(i32 %x, i32 %count), !dbg !78
 // CHECK:STDOUT:   ret i32 %F.call, !dbg !79
 // CHECK:STDOUT: }
@@ -196,21 +197,21 @@ fn M() {
 // CHECK:STDOUT: define linkonce_odr double @_CD.Main.c27b765f2159c9a0(double %x, i32 %count) #0 !dbg !88 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Int.as.OrderedWith.impl.Greater.call = icmp sgt i32 %count, 4, !dbg !92
-// CHECK:STDOUT:   br i1 %Int.as.OrderedWith.impl.Greater.call, label %if.then.loc48, label %if.else.loc48, !dbg !93
+// CHECK:STDOUT:   br i1 %Int.as.OrderedWith.impl.Greater.call, label %if.then.loc49, label %if.else.loc49, !dbg !93
 // CHECK:STDOUT:
-// CHECK:STDOUT: if.then.loc48:                                    ; preds = %entry
+// CHECK:STDOUT: if.then.loc49:                                    ; preds = %entry
 // CHECK:STDOUT:   ret double %x, !dbg !94
 // CHECK:STDOUT:
-// CHECK:STDOUT: if.else.loc48:                                    ; preds = %entry
+// CHECK:STDOUT: if.else.loc49:                                    ; preds = %entry
 // CHECK:STDOUT:   %Int.as.ModWith.impl.Op.call = srem i32 %count, 2, !dbg !95
 // CHECK:STDOUT:   %Int.as.EqWith.impl.Equal.call = icmp eq i32 %Int.as.ModWith.impl.Op.call, 0, !dbg !95
-// CHECK:STDOUT:   br i1 %Int.as.EqWith.impl.Equal.call, label %if.then.loc51, label %if.else.loc51, !dbg !96
+// CHECK:STDOUT:   br i1 %Int.as.EqWith.impl.Equal.call, label %if.then.loc52, label %if.else.loc52, !dbg !96
 // CHECK:STDOUT:
-// CHECK:STDOUT: if.then.loc51:                                    ; preds = %if.else.loc48
+// CHECK:STDOUT: if.then.loc52:                                    ; preds = %if.else.loc49
 // CHECK:STDOUT:   %E.call = call double @_CE.Main.c27b765f2159c9a0(double %x, i32 %count), !dbg !97
 // CHECK:STDOUT:   ret double %E.call, !dbg !98
 // CHECK:STDOUT:
-// CHECK:STDOUT: if.else.loc51:                                    ; preds = %if.else.loc48
+// CHECK:STDOUT: if.else.loc52:                                    ; preds = %if.else.loc49
 // CHECK:STDOUT:   %F.call = call double @_CF.Main.c27b765f2159c9a0(double %x, i32 %count), !dbg !99
 // CHECK:STDOUT:   ret double %F.call, !dbg !100
 // CHECK:STDOUT: }
@@ -226,21 +227,21 @@ fn M() {
 // CHECK:STDOUT: define linkonce_odr ptr @_CD.Main.2621742a01881e29(ptr %x, i32 %count) #0 !dbg !107 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Int.as.OrderedWith.impl.Greater.call = icmp sgt i32 %count, 4, !dbg !111
-// CHECK:STDOUT:   br i1 %Int.as.OrderedWith.impl.Greater.call, label %if.then.loc48, label %if.else.loc48, !dbg !112
+// CHECK:STDOUT:   br i1 %Int.as.OrderedWith.impl.Greater.call, label %if.then.loc49, label %if.else.loc49, !dbg !112
 // CHECK:STDOUT:
-// CHECK:STDOUT: if.then.loc48:                                    ; preds = %entry
+// CHECK:STDOUT: if.then.loc49:                                    ; preds = %entry
 // CHECK:STDOUT:   ret ptr %x, !dbg !113
 // CHECK:STDOUT:
-// CHECK:STDOUT: if.else.loc48:                                    ; preds = %entry
+// CHECK:STDOUT: if.else.loc49:                                    ; preds = %entry
 // CHECK:STDOUT:   %Int.as.ModWith.impl.Op.call = srem i32 %count, 2, !dbg !114
 // CHECK:STDOUT:   %Int.as.EqWith.impl.Equal.call = icmp eq i32 %Int.as.ModWith.impl.Op.call, 0, !dbg !114
-// CHECK:STDOUT:   br i1 %Int.as.EqWith.impl.Equal.call, label %if.then.loc51, label %if.else.loc51, !dbg !115
+// CHECK:STDOUT:   br i1 %Int.as.EqWith.impl.Equal.call, label %if.then.loc52, label %if.else.loc52, !dbg !115
 // CHECK:STDOUT:
-// CHECK:STDOUT: if.then.loc51:                                    ; preds = %if.else.loc48
+// CHECK:STDOUT: if.then.loc52:                                    ; preds = %if.else.loc49
 // CHECK:STDOUT:   %E.call = call ptr @_CE.Main.2621742a01881e29(ptr %x, i32 %count), !dbg !116
 // CHECK:STDOUT:   ret ptr %E.call, !dbg !117
 // CHECK:STDOUT:
-// CHECK:STDOUT: if.else.loc51:                                    ; preds = %if.else.loc48
+// CHECK:STDOUT: if.else.loc52:                                    ; preds = %if.else.loc49
 // CHECK:STDOUT:   %F.call = call ptr @_CF.Main.2621742a01881e29(ptr %x, i32 %count), !dbg !118
 // CHECK:STDOUT:   ret ptr %F.call, !dbg !119
 // CHECK:STDOUT: }
@@ -379,210 +380,210 @@ fn M() {
 // CHECK:STDOUT: !1 = !DIFile(filename: "call_recursive_sccs_deep.carbon", directory: "")
 // CHECK:STDOUT: !2 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !3 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !4 = distinct !DISubprogram(name: "M", linkageName: "_CM.Main", scope: null, file: !1, line: 73, type: !5, spFlags: DISPFlagDefinition, unit: !0)
+// CHECK:STDOUT: !4 = distinct !DISubprogram(name: "M", linkageName: "_CM.Main", scope: null, file: !1, line: 74, type: !5, spFlags: DISPFlagDefinition, unit: !0)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)
 // CHECK:STDOUT: !6 = !{null}
-// CHECK:STDOUT: !7 = !DILocation(line: 74, column: 3, scope: !4)
-// CHECK:STDOUT: !8 = !DILocation(line: 75, column: 3, scope: !4)
-// CHECK:STDOUT: !9 = !DILocation(line: 76, column: 3, scope: !4)
-// CHECK:STDOUT: !10 = !DILocation(line: 77, column: 3, scope: !4)
-// CHECK:STDOUT: !11 = !DILocation(line: 79, column: 5, scope: !4)
-// CHECK:STDOUT: !12 = !DILocation(line: 79, column: 3, scope: !4)
-// CHECK:STDOUT: !13 = !DILocation(line: 80, column: 5, scope: !4)
-// CHECK:STDOUT: !14 = !DILocation(line: 80, column: 3, scope: !4)
-// CHECK:STDOUT: !15 = !DILocation(line: 81, column: 5, scope: !4)
-// CHECK:STDOUT: !16 = !DILocation(line: 81, column: 3, scope: !4)
-// CHECK:STDOUT: !17 = !DILocation(line: 82, column: 5, scope: !4)
-// CHECK:STDOUT: !18 = !DILocation(line: 82, column: 3, scope: !4)
-// CHECK:STDOUT: !19 = !DILocation(line: 73, column: 1, scope: !4)
-// CHECK:STDOUT: !20 = distinct !DISubprogram(name: "Op", linkageName: "_COp.30d8007fdcc57f83:core.Destroy.Core", scope: null, file: !1, line: 75, type: !21, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !24)
+// CHECK:STDOUT: !7 = !DILocation(line: 75, column: 3, scope: !4)
+// CHECK:STDOUT: !8 = !DILocation(line: 76, column: 3, scope: !4)
+// CHECK:STDOUT: !9 = !DILocation(line: 77, column: 3, scope: !4)
+// CHECK:STDOUT: !10 = !DILocation(line: 78, column: 3, scope: !4)
+// CHECK:STDOUT: !11 = !DILocation(line: 80, column: 5, scope: !4)
+// CHECK:STDOUT: !12 = !DILocation(line: 80, column: 3, scope: !4)
+// CHECK:STDOUT: !13 = !DILocation(line: 81, column: 5, scope: !4)
+// CHECK:STDOUT: !14 = !DILocation(line: 81, column: 3, scope: !4)
+// CHECK:STDOUT: !15 = !DILocation(line: 82, column: 5, scope: !4)
+// CHECK:STDOUT: !16 = !DILocation(line: 82, column: 3, scope: !4)
+// CHECK:STDOUT: !17 = !DILocation(line: 83, column: 5, scope: !4)
+// CHECK:STDOUT: !18 = !DILocation(line: 83, column: 3, scope: !4)
+// CHECK:STDOUT: !19 = !DILocation(line: 74, column: 1, scope: !4)
+// CHECK:STDOUT: !20 = distinct !DISubprogram(name: "Op", linkageName: "_COp.30d8007fdcc57f83:core.Destroy.Core", scope: null, file: !1, line: 76, type: !21, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !24)
 // CHECK:STDOUT: !21 = !DISubroutineType(types: !22)
 // CHECK:STDOUT: !22 = !{null, !23}
 // CHECK:STDOUT: !23 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: null, size: 64)
 // CHECK:STDOUT: !24 = !{!25}
 // CHECK:STDOUT: !25 = !DILocalVariable(arg: 1, scope: !20, type: !23)
-// CHECK:STDOUT: !26 = !DILocation(line: 75, column: 3, scope: !20)
-// CHECK:STDOUT: !27 = distinct !DISubprogram(name: "Op", linkageName: "_COp.5e27612b9dd31a14:core.Destroy.Core", scope: null, file: !1, line: 74, type: !28, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !31)
+// CHECK:STDOUT: !26 = !DILocation(line: 76, column: 3, scope: !20)
+// CHECK:STDOUT: !27 = distinct !DISubprogram(name: "Op", linkageName: "_COp.5e27612b9dd31a14:core.Destroy.Core", scope: null, file: !1, line: 75, type: !28, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !31)
 // CHECK:STDOUT: !28 = !DISubroutineType(types: !29)
 // CHECK:STDOUT: !29 = !{null, !30}
 // CHECK:STDOUT: !30 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
 // CHECK:STDOUT: !31 = !{!32}
 // CHECK:STDOUT: !32 = !DILocalVariable(arg: 1, scope: !27, type: !30)
-// CHECK:STDOUT: !33 = !DILocation(line: 74, column: 3, scope: !27)
-// CHECK:STDOUT: !34 = distinct !DISubprogram(name: "A", linkageName: "_CA.Main.5bd8d5767580997a", scope: null, file: !1, line: 31, type: !35, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !37)
+// CHECK:STDOUT: !33 = !DILocation(line: 75, column: 3, scope: !27)
+// CHECK:STDOUT: !34 = distinct !DISubprogram(name: "A", linkageName: "_CA.Main.5bd8d5767580997a", scope: null, file: !1, line: 32, type: !35, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !37)
 // CHECK:STDOUT: !35 = !DISubroutineType(types: !36)
 // CHECK:STDOUT: !36 = !{!30, !30, !30}
 // CHECK:STDOUT: !37 = !{!38, !39}
 // CHECK:STDOUT: !38 = !DILocalVariable(arg: 1, scope: !34, type: !30)
 // CHECK:STDOUT: !39 = !DILocalVariable(arg: 2, scope: !34, type: !30)
-// CHECK:STDOUT: !40 = !DILocation(line: 32, column: 3, scope: !34)
-// CHECK:STDOUT: !41 = !DILocation(line: 33, column: 10, scope: !34)
-// CHECK:STDOUT: !42 = !DILocation(line: 33, column: 3, scope: !34)
-// CHECK:STDOUT: !43 = distinct !DISubprogram(name: "A", linkageName: "_CA.Main.c27b765f2159c9a0", scope: null, file: !1, line: 31, type: !44, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !46)
+// CHECK:STDOUT: !40 = !DILocation(line: 33, column: 3, scope: !34)
+// CHECK:STDOUT: !41 = !DILocation(line: 34, column: 10, scope: !34)
+// CHECK:STDOUT: !42 = !DILocation(line: 34, column: 3, scope: !34)
+// CHECK:STDOUT: !43 = distinct !DISubprogram(name: "A", linkageName: "_CA.Main.c27b765f2159c9a0", scope: null, file: !1, line: 32, type: !44, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !46)
 // CHECK:STDOUT: !44 = !DISubroutineType(types: !45)
 // CHECK:STDOUT: !45 = !{!23, !23, !30}
 // CHECK:STDOUT: !46 = !{!47, !48}
 // CHECK:STDOUT: !47 = !DILocalVariable(arg: 1, scope: !43, type: !23)
 // CHECK:STDOUT: !48 = !DILocalVariable(arg: 2, scope: !43, type: !30)
-// CHECK:STDOUT: !49 = !DILocation(line: 32, column: 3, scope: !43)
-// CHECK:STDOUT: !50 = !DILocation(line: 33, column: 10, scope: !43)
-// CHECK:STDOUT: !51 = !DILocation(line: 33, column: 3, scope: !43)
-// CHECK:STDOUT: !52 = distinct !DISubprogram(name: "A", linkageName: "_CA.Main.2621742a01881e29", scope: null, file: !1, line: 31, type: !44, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !53)
+// CHECK:STDOUT: !49 = !DILocation(line: 33, column: 3, scope: !43)
+// CHECK:STDOUT: !50 = !DILocation(line: 34, column: 10, scope: !43)
+// CHECK:STDOUT: !51 = !DILocation(line: 34, column: 3, scope: !43)
+// CHECK:STDOUT: !52 = distinct !DISubprogram(name: "A", linkageName: "_CA.Main.2621742a01881e29", scope: null, file: !1, line: 32, type: !44, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !53)
 // CHECK:STDOUT: !53 = !{!54, !55}
 // CHECK:STDOUT: !54 = !DILocalVariable(arg: 1, scope: !52, type: !23)
 // CHECK:STDOUT: !55 = !DILocalVariable(arg: 2, scope: !52, type: !30)
-// CHECK:STDOUT: !56 = !DILocation(line: 32, column: 3, scope: !52)
-// CHECK:STDOUT: !57 = !DILocation(line: 33, column: 10, scope: !52)
-// CHECK:STDOUT: !58 = !DILocation(line: 33, column: 3, scope: !52)
-// CHECK:STDOUT: !59 = distinct !DISubprogram(name: "B", linkageName: "_CB.Main.5bd8d5767580997a", scope: null, file: !1, line: 36, type: !60, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !62)
+// CHECK:STDOUT: !56 = !DILocation(line: 33, column: 3, scope: !52)
+// CHECK:STDOUT: !57 = !DILocation(line: 34, column: 10, scope: !52)
+// CHECK:STDOUT: !58 = !DILocation(line: 34, column: 3, scope: !52)
+// CHECK:STDOUT: !59 = distinct !DISubprogram(name: "B", linkageName: "_CB.Main.5bd8d5767580997a", scope: null, file: !1, line: 37, type: !60, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !62)
 // CHECK:STDOUT: !60 = !DISubroutineType(types: !61)
 // CHECK:STDOUT: !61 = !{null, !30, !30}
 // CHECK:STDOUT: !62 = !{!63, !64}
 // CHECK:STDOUT: !63 = !DILocalVariable(arg: 1, scope: !59, type: !30)
 // CHECK:STDOUT: !64 = !DILocalVariable(arg: 2, scope: !59, type: !30)
-// CHECK:STDOUT: !65 = !DILocation(line: 37, column: 3, scope: !59)
-// CHECK:STDOUT: !66 = !DILocation(line: 36, column: 1, scope: !59)
-// CHECK:STDOUT: !67 = distinct !DISubprogram(name: "D", linkageName: "_CD.Main.5bd8d5767580997a", scope: null, file: !1, line: 47, type: !35, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !68)
+// CHECK:STDOUT: !65 = !DILocation(line: 38, column: 3, scope: !59)
+// CHECK:STDOUT: !66 = !DILocation(line: 37, column: 1, scope: !59)
+// CHECK:STDOUT: !67 = distinct !DISubprogram(name: "D", linkageName: "_CD.Main.5bd8d5767580997a", scope: null, file: !1, line: 48, type: !35, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !68)
 // CHECK:STDOUT: !68 = !{!69, !70}
 // CHECK:STDOUT: !69 = !DILocalVariable(arg: 1, scope: !67, type: !30)
 // CHECK:STDOUT: !70 = !DILocalVariable(arg: 2, scope: !67, type: !30)
-// CHECK:STDOUT: !71 = !DILocation(line: 48, column: 7, scope: !67)
-// CHECK:STDOUT: !72 = !DILocation(line: 48, column: 6, scope: !67)
-// CHECK:STDOUT: !73 = !DILocation(line: 49, column: 5, scope: !67)
-// CHECK:STDOUT: !74 = !DILocation(line: 51, column: 7, scope: !67)
-// CHECK:STDOUT: !75 = !DILocation(line: 51, column: 6, scope: !67)
-// CHECK:STDOUT: !76 = !DILocation(line: 52, column: 12, scope: !67)
-// CHECK:STDOUT: !77 = !DILocation(line: 52, column: 5, scope: !67)
-// CHECK:STDOUT: !78 = !DILocation(line: 54, column: 12, scope: !67)
-// CHECK:STDOUT: !79 = !DILocation(line: 54, column: 5, scope: !67)
-// CHECK:STDOUT: !80 = distinct !DISubprogram(name: "B", linkageName: "_CB.Main.c27b765f2159c9a0", scope: null, file: !1, line: 36, type: !81, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !83)
+// CHECK:STDOUT: !71 = !DILocation(line: 49, column: 7, scope: !67)
+// CHECK:STDOUT: !72 = !DILocation(line: 49, column: 6, scope: !67)
+// CHECK:STDOUT: !73 = !DILocation(line: 50, column: 5, scope: !67)
+// CHECK:STDOUT: !74 = !DILocation(line: 52, column: 7, scope: !67)
+// CHECK:STDOUT: !75 = !DILocation(line: 52, column: 6, scope: !67)
+// CHECK:STDOUT: !76 = !DILocation(line: 53, column: 12, scope: !67)
+// CHECK:STDOUT: !77 = !DILocation(line: 53, column: 5, scope: !67)
+// CHECK:STDOUT: !78 = !DILocation(line: 55, column: 12, scope: !67)
+// CHECK:STDOUT: !79 = !DILocation(line: 55, column: 5, scope: !67)
+// CHECK:STDOUT: !80 = distinct !DISubprogram(name: "B", linkageName: "_CB.Main.c27b765f2159c9a0", scope: null, file: !1, line: 37, type: !81, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !83)
 // CHECK:STDOUT: !81 = !DISubroutineType(types: !82)
 // CHECK:STDOUT: !82 = !{null, !23, !30}
 // CHECK:STDOUT: !83 = !{!84, !85}
 // CHECK:STDOUT: !84 = !DILocalVariable(arg: 1, scope: !80, type: !23)
 // CHECK:STDOUT: !85 = !DILocalVariable(arg: 2, scope: !80, type: !30)
-// CHECK:STDOUT: !86 = !DILocation(line: 37, column: 3, scope: !80)
-// CHECK:STDOUT: !87 = !DILocation(line: 36, column: 1, scope: !80)
-// CHECK:STDOUT: !88 = distinct !DISubprogram(name: "D", linkageName: "_CD.Main.c27b765f2159c9a0", scope: null, file: !1, line: 47, type: !44, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !89)
+// CHECK:STDOUT: !86 = !DILocation(line: 38, column: 3, scope: !80)
+// CHECK:STDOUT: !87 = !DILocation(line: 37, column: 1, scope: !80)
+// CHECK:STDOUT: !88 = distinct !DISubprogram(name: "D", linkageName: "_CD.Main.c27b765f2159c9a0", scope: null, file: !1, line: 48, type: !44, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !89)
 // CHECK:STDOUT: !89 = !{!90, !91}
 // CHECK:STDOUT: !90 = !DILocalVariable(arg: 1, scope: !88, type: !23)
 // CHECK:STDOUT: !91 = !DILocalVariable(arg: 2, scope: !88, type: !30)
-// CHECK:STDOUT: !92 = !DILocation(line: 48, column: 7, scope: !88)
-// CHECK:STDOUT: !93 = !DILocation(line: 48, column: 6, scope: !88)
-// CHECK:STDOUT: !94 = !DILocation(line: 49, column: 5, scope: !88)
-// CHECK:STDOUT: !95 = !DILocation(line: 51, column: 7, scope: !88)
-// CHECK:STDOUT: !96 = !DILocation(line: 51, column: 6, scope: !88)
-// CHECK:STDOUT: !97 = !DILocation(line: 52, column: 12, scope: !88)
-// CHECK:STDOUT: !98 = !DILocation(line: 52, column: 5, scope: !88)
-// CHECK:STDOUT: !99 = !DILocation(line: 54, column: 12, scope: !88)
-// CHECK:STDOUT: !100 = !DILocation(line: 54, column: 5, scope: !88)
-// CHECK:STDOUT: !101 = distinct !DISubprogram(name: "B", linkageName: "_CB.Main.2621742a01881e29", scope: null, file: !1, line: 36, type: !81, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !102)
+// CHECK:STDOUT: !92 = !DILocation(line: 49, column: 7, scope: !88)
+// CHECK:STDOUT: !93 = !DILocation(line: 49, column: 6, scope: !88)
+// CHECK:STDOUT: !94 = !DILocation(line: 50, column: 5, scope: !88)
+// CHECK:STDOUT: !95 = !DILocation(line: 52, column: 7, scope: !88)
+// CHECK:STDOUT: !96 = !DILocation(line: 52, column: 6, scope: !88)
+// CHECK:STDOUT: !97 = !DILocation(line: 53, column: 12, scope: !88)
+// CHECK:STDOUT: !98 = !DILocation(line: 53, column: 5, scope: !88)
+// CHECK:STDOUT: !99 = !DILocation(line: 55, column: 12, scope: !88)
+// CHECK:STDOUT: !100 = !DILocation(line: 55, column: 5, scope: !88)
+// CHECK:STDOUT: !101 = distinct !DISubprogram(name: "B", linkageName: "_CB.Main.2621742a01881e29", scope: null, file: !1, line: 37, type: !81, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !102)
 // CHECK:STDOUT: !102 = !{!103, !104}
 // CHECK:STDOUT: !103 = !DILocalVariable(arg: 1, scope: !101, type: !23)
 // CHECK:STDOUT: !104 = !DILocalVariable(arg: 2, scope: !101, type: !30)
-// CHECK:STDOUT: !105 = !DILocation(line: 37, column: 3, scope: !101)
-// CHECK:STDOUT: !106 = !DILocation(line: 36, column: 1, scope: !101)
-// CHECK:STDOUT: !107 = distinct !DISubprogram(name: "D", linkageName: "_CD.Main.2621742a01881e29", scope: null, file: !1, line: 47, type: !44, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !108)
+// CHECK:STDOUT: !105 = !DILocation(line: 38, column: 3, scope: !101)
+// CHECK:STDOUT: !106 = !DILocation(line: 37, column: 1, scope: !101)
+// CHECK:STDOUT: !107 = distinct !DISubprogram(name: "D", linkageName: "_CD.Main.2621742a01881e29", scope: null, file: !1, line: 48, type: !44, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !108)
 // CHECK:STDOUT: !108 = !{!109, !110}
 // CHECK:STDOUT: !109 = !DILocalVariable(arg: 1, scope: !107, type: !23)
 // CHECK:STDOUT: !110 = !DILocalVariable(arg: 2, scope: !107, type: !30)
-// CHECK:STDOUT: !111 = !DILocation(line: 48, column: 7, scope: !107)
-// CHECK:STDOUT: !112 = !DILocation(line: 48, column: 6, scope: !107)
-// CHECK:STDOUT: !113 = !DILocation(line: 49, column: 5, scope: !107)
-// CHECK:STDOUT: !114 = !DILocation(line: 51, column: 7, scope: !107)
-// CHECK:STDOUT: !115 = !DILocation(line: 51, column: 6, scope: !107)
-// CHECK:STDOUT: !116 = !DILocation(line: 52, column: 12, scope: !107)
-// CHECK:STDOUT: !117 = !DILocation(line: 52, column: 5, scope: !107)
-// CHECK:STDOUT: !118 = !DILocation(line: 54, column: 12, scope: !107)
-// CHECK:STDOUT: !119 = !DILocation(line: 54, column: 5, scope: !107)
-// CHECK:STDOUT: !120 = distinct !DISubprogram(name: "C", linkageName: "_CC.Main.5bd8d5767580997a", scope: null, file: !1, line: 40, type: !60, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !121)
+// CHECK:STDOUT: !111 = !DILocation(line: 49, column: 7, scope: !107)
+// CHECK:STDOUT: !112 = !DILocation(line: 49, column: 6, scope: !107)
+// CHECK:STDOUT: !113 = !DILocation(line: 50, column: 5, scope: !107)
+// CHECK:STDOUT: !114 = !DILocation(line: 52, column: 7, scope: !107)
+// CHECK:STDOUT: !115 = !DILocation(line: 52, column: 6, scope: !107)
+// CHECK:STDOUT: !116 = !DILocation(line: 53, column: 12, scope: !107)
+// CHECK:STDOUT: !117 = !DILocation(line: 53, column: 5, scope: !107)
+// CHECK:STDOUT: !118 = !DILocation(line: 55, column: 12, scope: !107)
+// CHECK:STDOUT: !119 = !DILocation(line: 55, column: 5, scope: !107)
+// CHECK:STDOUT: !120 = distinct !DISubprogram(name: "C", linkageName: "_CC.Main.5bd8d5767580997a", scope: null, file: !1, line: 41, type: !60, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !121)
 // CHECK:STDOUT: !121 = !{!122, !123}
 // CHECK:STDOUT: !122 = !DILocalVariable(arg: 1, scope: !120, type: !30)
 // CHECK:STDOUT: !123 = !DILocalVariable(arg: 2, scope: !120, type: !30)
-// CHECK:STDOUT: !124 = !DILocation(line: 41, column: 7, scope: !120)
-// CHECK:STDOUT: !125 = !DILocation(line: 41, column: 6, scope: !120)
-// CHECK:STDOUT: !126 = !DILocation(line: 42, column: 5, scope: !120)
-// CHECK:STDOUT: !127 = !DILocation(line: 43, column: 10, scope: !120)
-// CHECK:STDOUT: !128 = !DILocation(line: 43, column: 5, scope: !120)
-// CHECK:STDOUT: !129 = !DILocation(line: 41, column: 3, scope: !120)
-// CHECK:STDOUT: !130 = !DILocation(line: 40, column: 1, scope: !120)
-// CHECK:STDOUT: !131 = distinct !DISubprogram(name: "E", linkageName: "_CE.Main.5bd8d5767580997a", scope: null, file: !1, line: 60, type: !35, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !132)
+// CHECK:STDOUT: !124 = !DILocation(line: 42, column: 7, scope: !120)
+// CHECK:STDOUT: !125 = !DILocation(line: 42, column: 6, scope: !120)
+// CHECK:STDOUT: !126 = !DILocation(line: 43, column: 5, scope: !120)
+// CHECK:STDOUT: !127 = !DILocation(line: 44, column: 10, scope: !120)
+// CHECK:STDOUT: !128 = !DILocation(line: 44, column: 5, scope: !120)
+// CHECK:STDOUT: !129 = !DILocation(line: 42, column: 3, scope: !120)
+// CHECK:STDOUT: !130 = !DILocation(line: 41, column: 1, scope: !120)
+// CHECK:STDOUT: !131 = distinct !DISubprogram(name: "E", linkageName: "_CE.Main.5bd8d5767580997a", scope: null, file: !1, line: 61, type: !35, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !132)
 // CHECK:STDOUT: !132 = !{!133, !134}
 // CHECK:STDOUT: !133 = !DILocalVariable(arg: 1, scope: !131, type: !30)
 // CHECK:STDOUT: !134 = !DILocalVariable(arg: 2, scope: !131, type: !30)
-// CHECK:STDOUT: !135 = !DILocation(line: 61, column: 10, scope: !131)
-// CHECK:STDOUT: !136 = !DILocation(line: 61, column: 3, scope: !131)
-// CHECK:STDOUT: !137 = distinct !DISubprogram(name: "F", linkageName: "_CF.Main.5bd8d5767580997a", scope: null, file: !1, line: 64, type: !35, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !138)
+// CHECK:STDOUT: !135 = !DILocation(line: 62, column: 10, scope: !131)
+// CHECK:STDOUT: !136 = !DILocation(line: 62, column: 3, scope: !131)
+// CHECK:STDOUT: !137 = distinct !DISubprogram(name: "F", linkageName: "_CF.Main.5bd8d5767580997a", scope: null, file: !1, line: 65, type: !35, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !138)
 // CHECK:STDOUT: !138 = !{!139, !140}
 // CHECK:STDOUT: !139 = !DILocalVariable(arg: 1, scope: !137, type: !30)
 // CHECK:STDOUT: !140 = !DILocalVariable(arg: 2, scope: !137, type: !30)
-// CHECK:STDOUT: !141 = !DILocation(line: 65, column: 10, scope: !137)
-// CHECK:STDOUT: !142 = !DILocation(line: 65, column: 3, scope: !137)
-// CHECK:STDOUT: !143 = distinct !DISubprogram(name: "C", linkageName: "_CC.Main.c27b765f2159c9a0", scope: null, file: !1, line: 40, type: !81, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !144)
+// CHECK:STDOUT: !141 = !DILocation(line: 66, column: 10, scope: !137)
+// CHECK:STDOUT: !142 = !DILocation(line: 66, column: 3, scope: !137)
+// CHECK:STDOUT: !143 = distinct !DISubprogram(name: "C", linkageName: "_CC.Main.c27b765f2159c9a0", scope: null, file: !1, line: 41, type: !81, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !144)
 // CHECK:STDOUT: !144 = !{!145, !146}
 // CHECK:STDOUT: !145 = !DILocalVariable(arg: 1, scope: !143, type: !23)
 // CHECK:STDOUT: !146 = !DILocalVariable(arg: 2, scope: !143, type: !30)
-// CHECK:STDOUT: !147 = !DILocation(line: 41, column: 7, scope: !143)
-// CHECK:STDOUT: !148 = !DILocation(line: 41, column: 6, scope: !143)
-// CHECK:STDOUT: !149 = !DILocation(line: 42, column: 5, scope: !143)
-// CHECK:STDOUT: !150 = !DILocation(line: 43, column: 10, scope: !143)
-// CHECK:STDOUT: !151 = !DILocation(line: 43, column: 5, scope: !143)
-// CHECK:STDOUT: !152 = !DILocation(line: 41, column: 3, scope: !143)
-// CHECK:STDOUT: !153 = !DILocation(line: 40, column: 1, scope: !143)
-// CHECK:STDOUT: !154 = distinct !DISubprogram(name: "E", linkageName: "_CE.Main.c27b765f2159c9a0", scope: null, file: !1, line: 60, type: !44, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !155)
+// CHECK:STDOUT: !147 = !DILocation(line: 42, column: 7, scope: !143)
+// CHECK:STDOUT: !148 = !DILocation(line: 42, column: 6, scope: !143)
+// CHECK:STDOUT: !149 = !DILocation(line: 43, column: 5, scope: !143)
+// CHECK:STDOUT: !150 = !DILocation(line: 44, column: 10, scope: !143)
+// CHECK:STDOUT: !151 = !DILocation(line: 44, column: 5, scope: !143)
+// CHECK:STDOUT: !152 = !DILocation(line: 42, column: 3, scope: !143)
+// CHECK:STDOUT: !153 = !DILocation(line: 41, column: 1, scope: !143)
+// CHECK:STDOUT: !154 = distinct !DISubprogram(name: "E", linkageName: "_CE.Main.c27b765f2159c9a0", scope: null, file: !1, line: 61, type: !44, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !155)
 // CHECK:STDOUT: !155 = !{!156, !157}
 // CHECK:STDOUT: !156 = !DILocalVariable(arg: 1, scope: !154, type: !23)
 // CHECK:STDOUT: !157 = !DILocalVariable(arg: 2, scope: !154, type: !30)
-// CHECK:STDOUT: !158 = !DILocation(line: 61, column: 10, scope: !154)
-// CHECK:STDOUT: !159 = !DILocation(line: 61, column: 3, scope: !154)
-// CHECK:STDOUT: !160 = distinct !DISubprogram(name: "F", linkageName: "_CF.Main.c27b765f2159c9a0", scope: null, file: !1, line: 64, type: !44, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !161)
+// CHECK:STDOUT: !158 = !DILocation(line: 62, column: 10, scope: !154)
+// CHECK:STDOUT: !159 = !DILocation(line: 62, column: 3, scope: !154)
+// CHECK:STDOUT: !160 = distinct !DISubprogram(name: "F", linkageName: "_CF.Main.c27b765f2159c9a0", scope: null, file: !1, line: 65, type: !44, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !161)
 // CHECK:STDOUT: !161 = !{!162, !163}
 // CHECK:STDOUT: !162 = !DILocalVariable(arg: 1, scope: !160, type: !23)
 // CHECK:STDOUT: !163 = !DILocalVariable(arg: 2, scope: !160, type: !30)
-// CHECK:STDOUT: !164 = !DILocation(line: 65, column: 10, scope: !160)
-// CHECK:STDOUT: !165 = !DILocation(line: 65, column: 3, scope: !160)
-// CHECK:STDOUT: !166 = distinct !DISubprogram(name: "C", linkageName: "_CC.Main.2621742a01881e29", scope: null, file: !1, line: 40, type: !81, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !167)
+// CHECK:STDOUT: !164 = !DILocation(line: 66, column: 10, scope: !160)
+// CHECK:STDOUT: !165 = !DILocation(line: 66, column: 3, scope: !160)
+// CHECK:STDOUT: !166 = distinct !DISubprogram(name: "C", linkageName: "_CC.Main.2621742a01881e29", scope: null, file: !1, line: 41, type: !81, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !167)
 // CHECK:STDOUT: !167 = !{!168, !169}
 // CHECK:STDOUT: !168 = !DILocalVariable(arg: 1, scope: !166, type: !23)
 // CHECK:STDOUT: !169 = !DILocalVariable(arg: 2, scope: !166, type: !30)
-// CHECK:STDOUT: !170 = !DILocation(line: 41, column: 7, scope: !166)
-// CHECK:STDOUT: !171 = !DILocation(line: 41, column: 6, scope: !166)
-// CHECK:STDOUT: !172 = !DILocation(line: 42, column: 5, scope: !166)
-// CHECK:STDOUT: !173 = !DILocation(line: 43, column: 10, scope: !166)
-// CHECK:STDOUT: !174 = !DILocation(line: 43, column: 5, scope: !166)
-// CHECK:STDOUT: !175 = !DILocation(line: 41, column: 3, scope: !166)
-// CHECK:STDOUT: !176 = !DILocation(line: 40, column: 1, scope: !166)
-// CHECK:STDOUT: !177 = distinct !DISubprogram(name: "E", linkageName: "_CE.Main.2621742a01881e29", scope: null, file: !1, line: 60, type: !44, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !178)
+// CHECK:STDOUT: !170 = !DILocation(line: 42, column: 7, scope: !166)
+// CHECK:STDOUT: !171 = !DILocation(line: 42, column: 6, scope: !166)
+// CHECK:STDOUT: !172 = !DILocation(line: 43, column: 5, scope: !166)
+// CHECK:STDOUT: !173 = !DILocation(line: 44, column: 10, scope: !166)
+// CHECK:STDOUT: !174 = !DILocation(line: 44, column: 5, scope: !166)
+// CHECK:STDOUT: !175 = !DILocation(line: 42, column: 3, scope: !166)
+// CHECK:STDOUT: !176 = !DILocation(line: 41, column: 1, scope: !166)
+// CHECK:STDOUT: !177 = distinct !DISubprogram(name: "E", linkageName: "_CE.Main.2621742a01881e29", scope: null, file: !1, line: 61, type: !44, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !178)
 // CHECK:STDOUT: !178 = !{!179, !180}
 // CHECK:STDOUT: !179 = !DILocalVariable(arg: 1, scope: !177, type: !23)
 // CHECK:STDOUT: !180 = !DILocalVariable(arg: 2, scope: !177, type: !30)
-// CHECK:STDOUT: !181 = !DILocation(line: 61, column: 10, scope: !177)
-// CHECK:STDOUT: !182 = !DILocation(line: 61, column: 3, scope: !177)
-// CHECK:STDOUT: !183 = distinct !DISubprogram(name: "F", linkageName: "_CF.Main.2621742a01881e29", scope: null, file: !1, line: 64, type: !44, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !184)
+// CHECK:STDOUT: !181 = !DILocation(line: 62, column: 10, scope: !177)
+// CHECK:STDOUT: !182 = !DILocation(line: 62, column: 3, scope: !177)
+// CHECK:STDOUT: !183 = distinct !DISubprogram(name: "F", linkageName: "_CF.Main.2621742a01881e29", scope: null, file: !1, line: 65, type: !44, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !184)
 // CHECK:STDOUT: !184 = !{!185, !186}
 // CHECK:STDOUT: !185 = !DILocalVariable(arg: 1, scope: !183, type: !23)
 // CHECK:STDOUT: !186 = !DILocalVariable(arg: 2, scope: !183, type: !30)
-// CHECK:STDOUT: !187 = !DILocation(line: 65, column: 10, scope: !183)
-// CHECK:STDOUT: !188 = !DILocation(line: 65, column: 3, scope: !183)
-// CHECK:STDOUT: !189 = distinct !DISubprogram(name: "G", linkageName: "_CG.Main.5bd8d5767580997a", scope: null, file: !1, line: 68, type: !35, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !190)
+// CHECK:STDOUT: !187 = !DILocation(line: 66, column: 10, scope: !183)
+// CHECK:STDOUT: !188 = !DILocation(line: 66, column: 3, scope: !183)
+// CHECK:STDOUT: !189 = distinct !DISubprogram(name: "G", linkageName: "_CG.Main.5bd8d5767580997a", scope: null, file: !1, line: 69, type: !35, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !190)
 // CHECK:STDOUT: !190 = !{!191, !192}
 // CHECK:STDOUT: !191 = !DILocalVariable(arg: 1, scope: !189, type: !30)
 // CHECK:STDOUT: !192 = !DILocalVariable(arg: 2, scope: !189, type: !30)
-// CHECK:STDOUT: !193 = !DILocation(line: 69, column: 15, scope: !189)
-// CHECK:STDOUT: !194 = !DILocation(line: 69, column: 10, scope: !189)
-// CHECK:STDOUT: !195 = !DILocation(line: 69, column: 3, scope: !189)
-// CHECK:STDOUT: !196 = distinct !DISubprogram(name: "G", linkageName: "_CG.Main.c27b765f2159c9a0", scope: null, file: !1, line: 68, type: !44, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !197)
+// CHECK:STDOUT: !193 = !DILocation(line: 70, column: 15, scope: !189)
+// CHECK:STDOUT: !194 = !DILocation(line: 70, column: 10, scope: !189)
+// CHECK:STDOUT: !195 = !DILocation(line: 70, column: 3, scope: !189)
+// CHECK:STDOUT: !196 = distinct !DISubprogram(name: "G", linkageName: "_CG.Main.c27b765f2159c9a0", scope: null, file: !1, line: 69, type: !44, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !197)
 // CHECK:STDOUT: !197 = !{!198, !199}
 // CHECK:STDOUT: !198 = !DILocalVariable(arg: 1, scope: !196, type: !23)
 // CHECK:STDOUT: !199 = !DILocalVariable(arg: 2, scope: !196, type: !30)
-// CHECK:STDOUT: !200 = !DILocation(line: 69, column: 15, scope: !196)
-// CHECK:STDOUT: !201 = !DILocation(line: 69, column: 10, scope: !196)
-// CHECK:STDOUT: !202 = !DILocation(line: 69, column: 3, scope: !196)
-// CHECK:STDOUT: !203 = distinct !DISubprogram(name: "G", linkageName: "_CG.Main.2621742a01881e29", scope: null, file: !1, line: 68, type: !44, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !204)
+// CHECK:STDOUT: !200 = !DILocation(line: 70, column: 15, scope: !196)
+// CHECK:STDOUT: !201 = !DILocation(line: 70, column: 10, scope: !196)
+// CHECK:STDOUT: !202 = !DILocation(line: 70, column: 3, scope: !196)
+// CHECK:STDOUT: !203 = distinct !DISubprogram(name: "G", linkageName: "_CG.Main.2621742a01881e29", scope: null, file: !1, line: 69, type: !44, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !204)
 // CHECK:STDOUT: !204 = !{!205, !206}
 // CHECK:STDOUT: !205 = !DILocalVariable(arg: 1, scope: !203, type: !23)
 // CHECK:STDOUT: !206 = !DILocalVariable(arg: 2, scope: !203, type: !30)
-// CHECK:STDOUT: !207 = !DILocation(line: 69, column: 15, scope: !203)
-// CHECK:STDOUT: !208 = !DILocation(line: 69, column: 10, scope: !203)
-// CHECK:STDOUT: !209 = !DILocation(line: 69, column: 3, scope: !203)
+// CHECK:STDOUT: !207 = !DILocation(line: 70, column: 15, scope: !203)
+// CHECK:STDOUT: !208 = !DILocation(line: 70, column: 10, scope: !203)
+// CHECK:STDOUT: !209 = !DILocation(line: 70, column: 3, scope: !203)
 // CHECK:STDOUT:
diff --git a/toolchain/runtimes/BUILD b/toolchain/runtimes/BUILD
index e1dbdb447cd2..1e8790254b5e 100644
--- a/toolchain/runtimes/BUILD
+++ b/toolchain/runtimes/BUILD
@@ -204,6 +204,13 @@ filegroup(
     ],
 )
 
+filegroup(
+    name = "carbon_core",
+    srcs = [
+        "//core:prelude_files",
+    ],
+)
+
 # Currently, we're only installing the subset of LLVM's libc internals needed to
 # build libc++. At some point, we should ship LLVM's libc itself, and that will
 # likely expand this to cover more of the source. However, we'll still want to
diff --git a/toolchain/runtimes/carbon_runtimes.bzl b/toolchain/runtimes/carbon_runtimes.bzl
index e870bb9440e1..7ba39a1ad985 100644
--- a/toolchain/runtimes/carbon_runtimes.bzl
+++ b/toolchain/runtimes/carbon_runtimes.bzl
@@ -48,6 +48,7 @@ CarbonRuntimesConfigInfo = provider(
     """,
     fields = [
         "builtins_archive",
+        "carbon_prelude_prebuilt",
         "clang_hdrs_prefix",
         "crt_copts",
         "crtbegin_src",
@@ -63,6 +64,7 @@ def _carbon_runtimes_config_impl(ctx):
     return [
         CarbonRuntimesConfigInfo(
             builtins_archive = ctx.files.builtins_archive[0],
+            carbon_prelude_prebuilt = ctx.files.carbon_prelude_prebuilt,
             clang_hdrs_prefix = ctx.attr.clang_hdrs_prefix,
             crt_copts = ctx.attr.crt_copts,
             crtbegin_src = ctx.files.crtbegin_src[0] if ctx.files.crtbegin_src else None,
@@ -78,6 +80,7 @@ carbon_runtimes_config = rule(
     implementation = _carbon_runtimes_config_impl,
     attrs = {
         "builtins_archive": attr.label(mandatory = True, allow_files = [".a"]),
+        "carbon_prelude_prebuilt": attr.label(allow_files = [".o"]),
         "clang_hdrs_prefix": attr.string(default = "include/"),
         "crt_copts": attr.string_list(default = []),
         "crtbegin_src": attr.label(allow_files = [".c"]),
@@ -170,6 +173,14 @@ def _carbon_runtimes_build_impl(ctx):
         ctx.actions.symlink(output = out_hdr, target_file = hdr)
         outputs.append(out_hdr)
 
+    for obj in config.carbon_prelude_prebuilt:
+        rel_path = obj.path
+        out_obj = ctx.actions.declare_file(
+            "{0}/core/{1}".format(prefix, rel_path),
+        )
+        ctx.actions.symlink(output = out_obj, target_file = obj)
+        outputs.append(out_obj)
+
     return [DefaultInfo(files = depset(outputs))]
 
 carbon_runtimes_build = rule(
diff --git a/toolchain/testing/file_test.cpp b/toolchain/testing/file_test.cpp
index 946c8304d0f4..44b09b096d61 100644
--- a/toolchain/testing/file_test.cpp
+++ b/toolchain/testing/file_test.cpp
@@ -47,6 +47,9 @@ struct SharedTestData {
   // Files in the prelude.
   llvm::SmallVector<std::string> prelude_files;
 
+  // Files in core not in the prelude.
+  llvm::SmallVector<std::string> core_files;
+
   // The installed files that tests can use.
   llvm::IntrusiveRefCntPtr<llvm::vfs::InMemoryFileSystem> file_system =
       new llvm::vfs::InMemoryFileSystem();
@@ -63,6 +66,12 @@ static auto GetSharedTestData(llvm::StringRef exe_path)
       CARBON_RETURN_IF_ERROR(AddFile(*data.file_system, file));
     }
 
+    CARBON_ASSIGN_OR_RETURN(data.core_files,
+                            data.installation.ReadCarbonCoreManifest());
+    for (const auto& file : data.core_files) {
+      CARBON_RETURN_IF_ERROR(AddFile(*data.file_system, file));
+    }
+
     llvm::SmallVector<std::string> clang_header_files;
     CARBON_ASSIGN_OR_RETURN(clang_header_files,
                             data.installation.ReadClangHeadersManifest());
@@ -166,6 +175,7 @@ auto ToolchainFileTest::Run(
   if (component_ == "check" || component_ == "lower") {
     filtered_test_args.reserve(test_args.size());
     bool found_prelude_flag = false;
+    bool found_include_core_flag = false;
     for (auto arg : test_args) {
       bool driver_flag = arg == "--custom-core" || arg == "--no-prelude-import";
       // A flag specified by a test prelude to indicate the intention to include
@@ -174,7 +184,9 @@ auto ToolchainFileTest::Run(
       if (driver_flag || full_prelude) {
         found_prelude_flag = true;
       }
-      if (!full_prelude) {
+      bool include_core = arg == "--include-carbon-core";
+      found_include_core_flag |= include_core;
+      if (!full_prelude && !include_core) {
         filtered_test_args.push_back(arg);
       }
     }
@@ -183,6 +195,13 @@ auto ToolchainFileTest::Run(
           "Include a prelude from //toolchain/testing/testdata/min_prelude "
           "to specify what should be imported into the test.");
     }
+    // The compile driver includes the carbon-core by default, but we invert
+    // this logic for the check and lower phases, meaning we detect the presence
+    // of `--include-carbon-core` in the arguments, and unless that is there
+    // we automatically append the `--no-include-carbon-core` flag.
+    if (!found_include_core_flag) {
+      filtered_test_args.push_back("--no-include-carbon-core");
+    }
   } else {
     filtered_test_args = test_args;
   }
@@ -266,7 +285,7 @@ auto ToolchainFileTest::GetDefaultArgs() const
   } else if (component_ == "lower") {
     args.insert(args.end(), {"--dump-llvm-ir", "--target=x86_64-linux-gnu"});
   } else if (component_ == "codegen") {
-    // codegen tests specify flags as needed.
+    args.insert(args.end(), {"--no-include-carbon-core"});
   } else {
     CARBON_FATAL("Unexpected test component {0}: {1}", component_, test_name());
   }