This is a preparatory step for using the HashMap clas with Literal keys in the
full code generator. It removes some duplicated code already and removes the
need for 2 HashMaps at each use, which was overly complicated.

Removed one dead function on the way.

Review URL: https://chromiumcodereview.appspot.com/9639011

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10973 ce2b1a6d-e550-0410-aec6-3dcde31c8c00