Fix for 3303 MultithreadedParallelIsolates has a race condition.

src/arm/deoptimizer-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"
 
 #include "codegen.h"
 #include "deoptimizer.h"
 #include "full-codegen.h"
 #include "safepoint-table.h"
@@ skipping 13 matching lines @@
 void Deoptimizer::PatchCodeForDeoptimization(Isolate* isolate, Code* code) {
   Address code_start_address = code->instruction_start();
   // Invalidate the relocation information, as it will become invalid by the
   // code patching below, and is not needed any more.
   code->InvalidateRelocation();
 
   if (FLAG_zap_code_space) {
     // Fail hard and early if we enter this code object again.
     byte* pointer = code->FindCodeAgeSequence();
     if (pointer != NULL) {
-      pointer += kNoCodeAgeSequenceLength * Assembler::kInstrSize;
+      pointer += kNoCodeAgeSequenceLength;
     } else {
       pointer = code->instruction_start();
     }
     CodePatcher patcher(pointer, 1);
     patcher.masm()->bkpt(0);
 
     DeoptimizationInputData* data =
         DeoptimizationInputData::cast(code->deoptimization_data());
     int osr_offset = data->OsrPcOffset()->value();
     if (osr_offset > 0) {
@@ skipping 308 matching lines @@
 
 void FrameDescription::SetCallerConstantPool(unsigned offset, intptr_t value) {
   ASSERT(FLAG_enable_ool_constant_pool);
   SetFrameSlot(offset, value);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal