Upgrade Symbol implementation to match current ES6 behavior.

src/stub-cache.cc

Index: src/stub-cache.cc
diff --git a/src/stub-cache.cc b/src/stub-cache.cc
index b83a5e142017b6cbe5b37b0e256b9ac7373f73fa..84ddc80614f3a7c9c216a50a1f4e77108308a044 100644
--- a/src/stub-cache.cc
+++ b/src/stub-cache.cc
@@ -247,8 +247,6 @@ Handle<Code> StubCache::ComputeKeyedStoreElement(
 }
 
 
-#define CALL_LOGGER_TAG(kind, type) (Logger::KEYED_##type)
-
 static void FillCache(Isolate* isolate, Handle<Code> code) {
   Handle<UnseededNumberDictionary> dictionary =
       UnseededNumberDictionary::Set(isolate->factory()->non_monomorphic_cache(),
@@ -744,9 +742,6 @@ Handle<Code> StubCompiler::CompileStoreMegamorphic(Code::Flags flags) {
 }
 
 
-#undef CALL_LOGGER_TAG
-
-
 Handle<Code> StubCompiler::GetCodeWithFlags(Code::Flags flags,
                                             const char* name) {
   // Create code object in the heap.