Fix for 3303 MultithreadedParallelIsolates has a race condition.

src/arm/builtins-arm.cc

 // Copyright 2012 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.
 
 #include "v8.h"
 
 #if V8_TARGET_ARCH_ARM
 
 #include "codegen.h"
 #include "debug.h"
@@ skipping 880 matching lines @@
   __ mov(r1, Operand(ExternalReference::isolate_address(masm->isolate())));
   __ CallCFunction(ExternalReference::get_mark_code_as_executed_function(
         masm->isolate()), 2);
   __ ldm(ia_w, sp, r0.bit() | r1.bit() | fp.bit() | lr.bit());
 
   // Perform prologue operations usually performed by the young code stub.
   __ PushFixedFrame(r1);
   __ add(fp, sp, Operand(StandardFrameConstants::kFixedFrameSizeFromFp));
 
   // Jump to point after the code-age stub.
-  __ add(r0, r0, Operand(kNoCodeAgeSequenceLength * Assembler::kInstrSize));
+  __ add(r0, r0, Operand(kNoCodeAgeSequenceLength));
   __ mov(pc, r0);
 }
 
 
 void Builtins::Generate_MarkCodeAsExecutedTwice(MacroAssembler* masm) {
   GenerateMakeCodeYoungAgainCommon(masm);
 }
 
 
 static void Generate_NotifyStubFailureHelper(MacroAssembler* masm,
@@ skipping 639 matching lines @@
     __ bkpt(0);
   }
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM