Passing "--simulator=arm" has the same effect as setting
"-S simulator=arm --arch=arm" and closely mirrors the behavior
of the scons build causing less confusion when running tests.
Review URL: http://codereview.chromium.org/1654

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@221 ce2b1a6d-e550-0410-aec6-3dcde31c8c00