This is a very mechanical change to reduce the number of calls to
Isolate::Current that come with every plain new-allocation.

BUG=v8:1802
Review URL: https://chromiumcodereview.appspot.com/9491004

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10857 ce2b1a6d-e550-0410-aec6-3dcde31c8c00