Test --trace directly (#933)

executable_semantics/testdata/basic_syntax/trace.carbon

@@ -0,0 +1,33 @@
+// 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
+//
+// RUN: executable_semantics --trace %s 2>&1 | \
+// RUN:   FileCheck --match-full-lines --allow-unused-prefixes %s
+//
+// A lot of output is elided: this is only checking for a few things for simple
+// sanity checking on --trace output.
+//
+// NOAUTOUPDATE
+// CHECK: ********** source program **********
+// CHECK: fn Print (format_str: String) {
+// CHECK: ********** type checking **********
+// CHECK: checking pattern (format_str: String)
+// CHECK: types: Print: fn (String) -> ()
+// CHECK: ********** type checking complete **********
+// CHECK: fn Print (format_str: String) {
+// CHECK: ********** starting execution **********
+// CHECK: ********** initializing globals **********
+// CHECK: ********** calling main function **********
+// CHECK: {
+// CHECK: stack:
+// CHECK: heap: fun<Print>, fun<Main>
+// CHECK: }
+// CHECK: --- step exp Main() (<Main()>:0) --->
+// CHECK: result: 0
+
+package ExecutableSemanticsTest api;
+
+fn Main() -> i32 {
+  return 0;
+}