Do not go to slow mode and back to fast in initializer blocks.

src/runtime.cc

Index: src/runtime.cc
diff --git a/src/runtime.cc b/src/runtime.cc
index ab462490e193fc78d76279939cc3f4678edfcc59..87f2d541e8abd82fcf924cf73324723a48321dad 100644
--- a/src/runtime.cc
+++ b/src/runtime.cc
@@ -5032,15 +5032,6 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_ToFastProperties) {
 }
 
 
-RUNTIME_FUNCTION(MaybeObject*, Runtime_ToSlowProperties) {
-  ASSERT(args.length() == 1);
-  Object* obj = args[0];
-  return (obj->IsJSObject() && !obj->IsJSGlobalProxy())
-      ? JSObject::cast(obj)->NormalizeProperties(CLEAR_INOBJECT_PROPERTIES, 0)
-      : obj;
-}
-
-
 RUNTIME_FUNCTION(MaybeObject*, Runtime_ToBool) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 1);