Make the runtime entry for setting/changing accessors "atomic".

src/ia32/full-codegen-ia32.cc

Index: src/ia32/full-codegen-ia32.cc
diff --git a/src/ia32/full-codegen-ia32.cc b/src/ia32/full-codegen-ia32.cc
index 86ca138ad25495ea867d0fd43a908edec1a4fb2d..b55f4280f172fcefd8e08178630552d29b9f9313 100644
--- a/src/ia32/full-codegen-ia32.cc
+++ b/src/ia32/full-codegen-ia32.cc
@@ -1519,10 +1519,13 @@ void FullCodeGenerator::VisitObjectLiteral(ObjectLiteral* expr) {
       case ObjectLiteral::Property::GETTER:
         __ push(Operand(esp, 0));  // Duplicate receiver.
         VisitForStackValue(key);
-        __ push(Immediate(property->kind() == ObjectLiteral::Property::SETTER ?
-                          Smi::FromInt(1) :
-                          Smi::FromInt(0)));
-        VisitForStackValue(value);
+        if (property->kind() == ObjectLiteral::Property::GETTER) {
+          VisitForStackValue(value);
+          __ push(Immediate(isolate()->factory()->null_value()));
+        } else {
+          __ push(Immediate(isolate()->factory()->null_value()));
+          VisitForStackValue(value);
+        }
         __ push(Immediate(Smi::FromInt(NONE)));
         __ CallRuntime(Runtime::kDefineOrRedefineAccessorProperty, 5);
         break;