[interpreter] Allow mixed stacks if bytecode is preserved.

test/cctest/test-compiler.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 763 matching lines @@
   v8::Local<v8::Context> context = isolate->GetCurrentContext();
   v8::Local<v8::FunctionTemplate> t =
       v8::FunctionTemplate::New(isolate, IsBaselineCompiled);
   CHECK(context->Global()
             ->Set(context, v8_str("IsBaselineCompiled"),
                   t->GetFunction(context).ToLocalChecked())
             .FromJust());
 }
 
 TEST(IgnitionBaselineOnReturn) {
+  // TODO(4280): Remove this entire test once --ignition-preserve-bytecode is
+  // the default and the flag is removed. This test doesn't provide benefit any
+  // longer once {InterpreterActivationsFinder} is gone.
+  if (FLAG_ignition_preserve_bytecode) return;
   FLAG_allow_natives_syntax = true;
   FLAG_always_opt = false;
   CcTest::InitializeVM();
   FLAG_ignition = true;
   Isolate* isolate = CcTest::i_isolate();
   isolate->interpreter()->Initialize();
   v8::HandleScope scope(CcTest::isolate());
   InstallIsBaselineCompiledHelper(CcTest::isolate());
 
   CompileRun(
@@ skipping 36 matching lines @@
   CHECK_NE(*isolate->builtins()->InterpreterEntryTrampoline(), f1->code());
   CHECK_EQ(*isolate->builtins()->InterpreterEntryTrampoline(), f2->code());
   CHECK_EQ(23.0, GetGlobalProperty("result1")->Number());
 
   // Function {f2} will self-heal now.
   CompileRun("var result2 = f2()");
   CHECK_NE(*isolate->builtins()->InterpreterEntryTrampoline(), f1->code());
   CHECK_NE(*isolate->builtins()->InterpreterEntryTrampoline(), f2->code());
   CHECK_EQ(23.0, GetGlobalProperty("result2")->Number());
 }