Explicitly set expected number of properties for instances of builtin types.

src/runtime.cc

Index: src/runtime.cc
diff --git a/src/runtime.cc b/src/runtime.cc
index 1122d331a4fd0519799fc6bf2b97ace49889109c..f908036469a07699028bc95517926ba648ef6304 100644
--- a/src/runtime.cc
+++ b/src/runtime.cc
@@ -1701,7 +1701,6 @@ static Object* Runtime_SetCode(Arguments args) {
     RUNTIME_ASSERT(code->IsJSFunction());
     Handle<JSFunction> fun = Handle<JSFunction>::cast(code);
     Handle<SharedFunctionInfo> shared(fun->shared());
-    SetExpectedNofProperties(target, shared->expected_nof_properties());
 
     if (!EnsureCompiled(shared, KEEP_EXCEPTION)) {
       return Failure::Exception();
@@ -1746,6 +1745,17 @@ static Object* Runtime_SetCode(Arguments args) {
 }
 
 
+static Object* Runtime_SetExpectedNumberOfProperties(Arguments args) {
+  HandleScope scope;
+  ASSERT(args.length() == 2);
+  CONVERT_ARG_CHECKED(JSFunction, function, 0);
+  CONVERT_SMI_CHECKED(num, args[1]);
+  RUNTIME_ASSERT(num >= 0);
+  SetExpectedNofProperties(function, num);
+  return Heap::undefined_value();
+}
+
+
 static Object* CharFromCode(Object* char_code) {
   uint32_t code;
   if (char_code->ToArrayIndex(&code)) {