[compiler] Remove --ignition-preserve-bytecode flag.

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 601 matching lines @@
   CheckCodeForUnsafeLiteral(GetJSFunction(context->Global(), "f"));
   CompileRun("function f(x) { a = 12345678 + x}; f(1);");
   CheckCodeForUnsafeLiteral(GetJSFunction(context->Global(), "f"));
   CompileRun("function f(x) { var arguments = 1; x += 12345678}; f(1);");
   CheckCodeForUnsafeLiteral(GetJSFunction(context->Global(), "f"));
   CompileRun("function f(x) { var arguments = 1; x = 12345678}; f(1);");
   CheckCodeForUnsafeLiteral(GetJSFunction(context->Global(), "f"));
 }
 #endif
 
-static void IsBaselineCompiled(
-    const v8::FunctionCallbackInfo<v8::Value>& args) {
-  Handle<Object> object = v8::Utils::OpenHandle(*args[0]);
-  Handle<JSFunction> function = Handle<JSFunction>::cast(object);
-  bool is_baseline = function->shared()->code()->kind() == Code::FUNCTION;
-  return args.GetReturnValue().Set(is_baseline);
-}
-
-static void InstallIsBaselineCompiledHelper(v8::Isolate* isolate) {
-  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(
-      "var is_baseline_in_function, is_baseline_after_return;\n"
-      "var return_val;\n"
-      "function f() {\n"
-      "  %CompileBaseline(f);\n"
-      "  is_baseline_in_function = IsBaselineCompiled(f);\n"
-      "  return 1234;\n"
-      "};\n"
-      "return_val = f();\n"
-      "is_baseline_after_return = IsBaselineCompiled(f);\n");
-  CHECK_EQ(false, GetGlobalProperty("is_baseline_in_function")->BooleanValue());
-  CHECK_EQ(true, GetGlobalProperty("is_baseline_after_return")->BooleanValue());
-  CHECK_EQ(1234.0, GetGlobalProperty("return_val")->Number());
-}
-
 TEST(IgnitionEntryTrampolineSelfHealing) {
   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());
 
   CompileRun(
@@ skipping 35 matching lines @@
   CompileRun("foo()");
   CHECK_EQ(2, foo->feedback_vector()->invocation_count());
   CompileRun("bar()");
   CHECK_EQ(2, foo->feedback_vector()->invocation_count());
   CompileRun("foo(); foo()");
   CHECK_EQ(4, foo->feedback_vector()->invocation_count());
   CompileRun("%BaselineFunctionOnNextCall(foo);");
   CompileRun("foo();");
   CHECK_EQ(5, foo->feedback_vector()->invocation_count());
 }