Fix for 3303 MultithreadedParallelIsolates has a race condition.

src/arm64/macro-assembler-arm64.h

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_ARM64_MACRO_ASSEMBLER_ARM64_H_
 #define V8_ARM64_MACRO_ASSEMBLER_ARM64_H_
 
 #include <vector>
 
 #include "v8globals.h"
@@ skipping 1963 matching lines @@
   // the stub address that is normally embedded in the instruction stream. This
   // can be used by debug code to verify code age sequences.
   static void EmitCodeAgeSequence(Assembler* assm, Code* stub);
 
   // Call EmitCodeAgeSequence from a MacroAssembler context.
   void EmitCodeAgeSequence(Code* stub);
 
   // Return true if the sequence is a young sequence geneated by
   // EmitFrameSetupForCodeAgePatching. Otherwise, this method asserts that the
   // sequence is a code age sequence (emitted by EmitCodeAgeSequence).
-  static bool IsYoungSequence(byte* sequence);
-
-#ifdef DEBUG
-  // Return true if the sequence is a code age sequence generated by
-  // EmitCodeAgeSequence.
-  static bool IsCodeAgeSequence(byte* sequence);
-#endif
+  static bool IsYoungSequence(Isolate* isolate, byte* sequence);
 
   // Jumps to found label if a prototype map has dictionary elements.
   void JumpIfDictionaryInPrototypeChain(Register object, Register scratch0,
                                         Register scratch1, Label* found);
 
  private:
   // Helpers for CopyFields.
   // These each implement CopyFields in a different way.
   void CopyFieldsLoopPairsHelper(Register dst, Register src, unsigned count,
                                  Register scratch1, Register scratch2,
@@ skipping 283 matching lines @@
 #error "Unsupported option"
 #define CODE_COVERAGE_STRINGIFY(x) #x
 #define CODE_COVERAGE_TOSTRING(x) CODE_COVERAGE_STRINGIFY(x)
 #define __FILE_LINE__ __FILE__ ":" CODE_COVERAGE_TOSTRING(__LINE__)
 #define ACCESS_MASM(masm) masm->stop(__FILE_LINE__); masm->
 #else
 #define ACCESS_MASM(masm) masm->
 #endif
 
 #endif  // V8_ARM64_MACRO_ASSEMBLER_ARM64_H_