[Interpreter]: Basic support for iterating interpreter stack frames for GC.

src/objects-inl.h

Index: src/objects-inl.h
diff --git a/src/objects-inl.h b/src/objects-inl.h
index 4f2bd7a29ce27cd6cb8c16e41c1ecdbc120c0024..5bebb35f0ce30239a9bb6e7068740b55727aef33 100644
--- a/src/objects-inl.h
+++ b/src/objects-inl.h
@@ -4994,12 +4994,8 @@ bool Code::IsCodeStubOrIC() {
 
 
 bool Code::IsJavaScriptCode() {
-  if (kind() == FUNCTION || kind() == OPTIMIZED_FUNCTION) {
-    return true;
-  }
-  Handle<Code> interpreter_entry =
-      GetIsolate()->builtins()->InterpreterEntryTrampoline();
-  return interpreter_entry.location() != nullptr && *interpreter_entry == this;
+  return kind() == FUNCTION || kind() == OPTIMIZED_FUNCTION ||
+         is_interpreter_entry_trampoline();
 }
 
 
@@ -5048,6 +5044,12 @@ inline bool Code::is_hydrogen_stub() {
 }
 
 
+inline bool Code::is_interpreter_entry_trampoline() {
+  Handle<Code> interpreter_entry =
+      GetIsolate()->builtins()->InterpreterEntryTrampoline();
+  return interpreter_entry.location() != nullptr && *interpreter_entry == this;
+}
+
 inline void Code::set_is_crankshafted(bool value) {
   int previous = READ_UINT32_FIELD(this, kKindSpecificFlags2Offset);
   int updated = IsCrankshaftedField::update(previous, value);