Deprecate old code aging mechanism.

src/objects-inl.h

Index: src/objects-inl.h
diff --git a/src/objects-inl.h b/src/objects-inl.h
index 47d119af52ba882525576ddbd9a21aae539e514f..9f4392a2bed9b22440f6c0299b65b11c310b575f 100644
--- a/src/objects-inl.h
+++ b/src/objects-inl.h
@@ -4778,17 +4778,6 @@ BuiltinFunctionId SharedFunctionInfo::builtin_function_id() {
 }
 
 
-int SharedFunctionInfo::code_age() {
-  return (compiler_hints() >> kCodeAgeShift) & kCodeAgeMask;
-}
-
-
-void SharedFunctionInfo::set_code_age(int code_age) {
-  int hints = compiler_hints() & ~(kCodeAgeMask << kCodeAgeShift);
-  set_compiler_hints(hints | ((code_age & kCodeAgeMask) << kCodeAgeShift));
-}
-
-
 int SharedFunctionInfo::ic_age() {
   return ICAgeBits::decode(counters());
 }