Allow all Names to be fast property names

test/mjsunit/fast-non-keyed.js

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 90 matching lines @@
 assertFalse(%HasFastProperties(keyed));
 
 var non_keyed = {};
 AddPropsNonKeyed(non_keyed);
 assertTrue(%HasFastProperties(non_keyed));
 
 var obj3 = {};
 AddProps3(obj3);
 assertTrue(%HasFastProperties(obj3));
 
-var bad_name = {};
-bad_name[".foo"] = 0;
-assertFalse(%HasFastProperties(bad_name));
+var funny_name = {};
+funny_name[".foo"] = 0;
+assertTrue(%HasFastProperties(funny_name));