[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 782 matching lines @@
   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());
+  // 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.
+  bool base = FLAG_ignition_preserve_bytecode;

[rmcilroy, 2016/08/22 15:33:03]

just do: "if (FLAG_ignition_preserve_bytecode) return" up at the top?

[Michael Starzinger, 2016/08/22 15:44:23]

Done.

+  CHECK_EQ(base, 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();
@@ skipping 16 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());
 }