Make assertion scopes thread safe.

src/ia32/macro-assembler-ia32.cc

Index: src/ia32/macro-assembler-ia32.cc
diff --git a/src/ia32/macro-assembler-ia32.cc b/src/ia32/macro-assembler-ia32.cc
index ec45eaab4631cb87cfaea81757e7ce6ae5e8e617..3a68487ef103557d23a4952354b89dd643aa697f 100644
--- a/src/ia32/macro-assembler-ia32.cc
+++ b/src/ia32/macro-assembler-ia32.cc
@@ -2493,7 +2493,7 @@ int MacroAssembler::SafepointRegisterStackIndex(int reg_code) {
 
 void MacroAssembler::LoadHeapObject(Register result,
                                     Handle<HeapObject> object) {
-  ALLOW_HANDLE_DEREF(isolate(), "embedding raw address");
+  AllowDeferredHandleDereference embedding_raw_address;
   if (isolate()->heap()->InNewSpace(*object)) {
     Handle<JSGlobalPropertyCell> cell =
         isolate()->factory()->NewJSGlobalPropertyCell(object);
@@ -2505,7 +2505,7 @@ void MacroAssembler::LoadHeapObject(Register result,
 
 
 void MacroAssembler::CmpHeapObject(Register reg, Handle<HeapObject> object) {
-  ALLOW_HANDLE_DEREF(isolate(), "using raw address");
+  AllowDeferredHandleDereference using_raw_address;
   if (isolate()->heap()->InNewSpace(*object)) {
     Handle<JSGlobalPropertyCell> cell =
         isolate()->factory()->NewJSGlobalPropertyCell(object);
@@ -2517,7 +2517,7 @@ void MacroAssembler::CmpHeapObject(Register reg, Handle<HeapObject> object) {
 
 
 void MacroAssembler::PushHeapObject(Handle<HeapObject> object) {
-  ALLOW_HANDLE_DEREF(isolate(), "using raw address");
+  AllowDeferredHandleDereference using_raw_address;
   if (isolate()->heap()->InNewSpace(*object)) {
     Handle<JSGlobalPropertyCell> cell =
         isolate()->factory()->NewJSGlobalPropertyCell(object);