Add code age subtype tracking to --track-gc-object-stats

src/arm/codegen-arm.cc

Index: src/arm/codegen-arm.cc
diff --git a/src/arm/codegen-arm.cc b/src/arm/codegen-arm.cc
index 717f286315e0840b83d142967e8185b9ddc7536b..44c331b75f541c1f741102fb2a23e959e74ebf81 100644
--- a/src/arm/codegen-arm.cc
+++ b/src/arm/codegen-arm.cc
@@ -871,7 +871,7 @@ bool Code::IsYoungSequence(byte* sequence) {
 void Code::GetCodeAgeAndParity(byte* sequence, Age* age,
                                MarkingParity* parity) {
   if (IsYoungSequence(sequence)) {
-    *age = kNoAge;
+    *age = kNoAgeCodeAge;
     *parity = NO_MARKING_PARITY;
   } else {
     Address target_address = Memory::Address_at(
@@ -888,7 +888,7 @@ void Code::PatchPlatformCodeAge(Isolate* isolate,
                                 MarkingParity parity) {
   uint32_t young_length;
   byte* young_sequence = GetNoCodeAgeSequence(&young_length);
-  if (age == kNoAge) {
+  if (age == kNoAgeCodeAge) {
     CopyBytes(sequence, young_sequence, young_length);
     CPU::FlushICache(sequence, young_length);
   } else {