Make assertion scopes thread safe.

src/ia32/assembler-ia32.h

Index: src/ia32/assembler-ia32.h
diff --git a/src/ia32/assembler-ia32.h b/src/ia32/assembler-ia32.h
index 8ded78558b4f58086c9a9fe947e2c980b1a48aba..91e79d20d1d25813deb8ed266ab4079592beade9 100644
--- a/src/ia32/assembler-ia32.h
+++ b/src/ia32/assembler-ia32.h
@@ -411,7 +411,7 @@ class Operand BASE_EMBEDDED {
   }
 
   static Operand Cell(Handle<JSGlobalPropertyCell> cell) {
-    ALLOW_HANDLE_DEREF(Isolate::Current(), "embedding raw address");
+    ALLOW_DEFERRED_HANDLE_DEREF(Isolate::Current(), "embedding raw address");
     return Operand(reinterpret_cast<int32_t>(cell.location()),
                    RelocInfo::GLOBAL_PROPERTY_CELL);
   }