Unify Action and Scope stacks, and eliminate Frame (#880)

Co-authored-by: Jon Meow <46229924+jonmeow@users.noreply.github.com>

executable_semantics/interpreter/resolve_control_flow.h

@@ -0,0 +1,19 @@
+// 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 EXECUTABLE_SEMANTICS_INTERPRETER_RESOLVE_CONTROL_FLOW_H_
+#define EXECUTABLE_SEMANTICS_INTERPRETER_RESOLVE_CONTROL_FLOW_H_
+
+#include "executable_semantics/ast/ast.h"
+#include "executable_semantics/common/nonnull.h"
+
+namespace Carbon {
+
+// Resolves non-local control-flow edges, such as `break` and `return`, in the
+// given AST.
+void ResolveControlFlow(AST& ast);
+
+}  // namespace Carbon
+
+#endif  // EXECUTABLE_SEMANTICS_INTERPRETER_RESOLVE_CONTROL_FLOW_H_