[Heap] Remove concept of MarkingParity.

src/x64/codegen-x64.cc

Index: src/x64/codegen-x64.cc
diff --git a/src/x64/codegen-x64.cc b/src/x64/codegen-x64.cc
index 16cf39c99fedcdcb571ff055b396b188c49bbfee..3532a96193d623838f2ebc5ad00caf2685d821cf 100644
--- a/src/x64/codegen-x64.cc
+++ b/src/x64/codegen-x64.cc
@@ -195,32 +195,26 @@ bool Code::IsYoungSequence(Isolate* isolate, byte* sequence) {
   return result;
 }
 
-
-void Code::GetCodeAgeAndParity(Isolate* isolate, byte* sequence, Age* age,
-                               MarkingParity* parity) {
+Code::Age Code::GetCodeAge(Isolate* isolate, byte* sequence) {
   if (IsYoungSequence(isolate, sequence)) {
-    *age = kNoAgeCodeAge;
-    *parity = NO_MARKING_PARITY;
+    return kNoAgeCodeAge;
   } else {
     sequence++;  // Skip the kCallOpcode byte
     Address target_address = sequence + *reinterpret_cast<int*>(sequence) +
         Assembler::kCallTargetAddressOffset;
     Code* stub = GetCodeFromTargetAddress(target_address);
-    GetCodeAgeAndParity(stub, age, parity);
+    return GetAgeOfCodeAgeStub(stub);
   }
 }
 
-
-void Code::PatchPlatformCodeAge(Isolate* isolate,
-                                byte* sequence,
-                                Code::Age age,
-                                MarkingParity parity) {
+void Code::PatchPlatformCodeAge(Isolate* isolate, byte* sequence,
+                                Code::Age age) {
   uint32_t young_length = isolate->code_aging_helper()->young_sequence_length();
   if (age == kNoAgeCodeAge) {
     isolate->code_aging_helper()->CopyYoungSequenceTo(sequence);
     Assembler::FlushICache(isolate, sequence, young_length);
   } else {
-    Code* stub = GetCodeAgeStub(isolate, age, parity);
+    Code* stub = GetCodeAgeStub(isolate, age);
     CodePatcher patcher(isolate, sequence, young_length);
     patcher.masm()->call(stub->instruction_start());
     patcher.masm()->Nop(