Support object literal map caching for literals with keys that are array indi...

Support object literal map caching for literals with keys that are array indices.

The caching code used to require that all keys in the literal were symbol strings
in order to be able to cache object literal maps.

Relaxed this requirement to allow array indices as well (as in { "1": "one", two: "two" }).

Changed the way 'number_of_properties' is calculated so that redundant property slots are not
allocated for array indices. 



Committed: http://code.google.com/p/v8/source/detail?r=5114

[Mads Ager (chromium), 2010-07-22 06:07:27]

Excellent! LGTM