Improve optimized code for comparison of an int32 against a constant, or comparison of two double constants.  Contributed by m.m.capewell.

Original codereview is http://codereview.chromium.org/7489045/.
This cl is just created in order to commit the change.

BUG=
TEST=

Review URL: http://codereview.chromium.org/8352040

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9718 ce2b1a6d-e550-0410-aec6-3dcde31c8c00