Introduce accessors on builtins instance

src/x64/macro-assembler-x64.h

 // Copyright 2011 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 1892 matching lines @@
       // Both expected and actual are in (different) registers. This
       // is the case when we invoke functions using call and apply.
       cmpq(expected.reg(), actual.reg());
       j(equal, &invoke);
       ASSERT(actual.reg().is(rax));
       ASSERT(expected.reg().is(rbx));
     }
   }
 
   if (!definitely_matches) {
-    Handle<Code> adaptor =
-        Handle<Code>(Isolate::Current()->builtins()->builtin(
-            Builtins::ArgumentsAdaptorTrampoline));
+    Handle<Code> adaptor = isolate()->builtins()->ArgumentsAdaptorTrampoline();
     if (!code_constant.is_null()) {
       movq(rdx, code_constant, RelocInfo::EMBEDDED_OBJECT);
       addq(rdx, Immediate(Code::kHeaderSize - kHeapObjectTag));
     } else if (!code_register.is(rdx)) {
       movq(rdx, code_register);
     }
 
     if (flag == CALL_FUNCTION) {
       if (call_wrapper != NULL) call_wrapper->BeforeCall(CallSize(adaptor));
       Call(adaptor, RelocInfo::CODE_TARGET);
       if (call_wrapper != NULL) call_wrapper->AfterCall();
       jmp(done);
     } else {
       Jump(adaptor, RelocInfo::CODE_TARGET);
     }
     bind(&invoke);
   }
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_X64_MACRO_ASSEMBLER_X64_H_