[Interpreter] Add IsInterpreted() to JSFunction and use to fix test-heap tests.

src/objects-inl.h

Index: src/objects-inl.h
diff --git a/src/objects-inl.h b/src/objects-inl.h
index 494e9311b235172d178d7afa67ac5be77204f69c..74711f2e9a31ffadd28ec5412e48067a9a0aa4be 100644
--- a/src/objects-inl.h
+++ b/src/objects-inl.h
@@ -6267,6 +6267,10 @@ void SharedFunctionInfo::ReplaceCode(Code* value) {
   if (is_compiled()) set_never_compiled(false);
 }
 
+bool SharedFunctionInfo::IsInterpreted() const {
+  return code()->is_interpreter_trampoline_builtin();
+}
+
 bool SharedFunctionInfo::HasBaselineCode() const {
   return code()->kind() == Code::FUNCTION;
 }
@@ -6508,6 +6512,10 @@ bool JSFunction::IsOptimized() {
   return code()->kind() == Code::OPTIMIZED_FUNCTION;
 }
 
+bool JSFunction::IsInterpreted() {
+  return code()->is_interpreter_trampoline_builtin();
+}
+
 bool JSFunction::IsMarkedForBaseline() {
   return code() ==
          GetIsolate()->builtins()->builtin(Builtins::kCompileBaseline);
@@ -6553,11 +6561,10 @@ void Map::InobjectSlackTrackingStep() {
 }
 
 AbstractCode* JSFunction::abstract_code() {
-  Code* code = this->code();
-  if (code->is_interpreter_trampoline_builtin()) {
+  if (IsInterpreted()) {
     return AbstractCode::cast(shared()->bytecode_array());
   } else {
-    return AbstractCode::cast(code);
+    return AbstractCode::cast(code());
   }
 }