Added USE_SIMULATOR macro that explicitly indicates that we wish to use the simulator as the execution engine. For example, this allows us to run with the ARM simulator on ARM.

Patch by Mark Lam <mark.lam@palm.com> from Hewlett-Packard Development Company, LP

Review URL: http://codereview.chromium.org/3825001


git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5620 ce2b1a6d-e550-0410-aec6-3dcde31c8c00