Small optimization of ARM compare stub. Reverse all references to

Small optimization of ARM compare stub.  Reverse all references to
left and right sides of the comparison to reflect reality.  Don't
check explicitly for NaNs when using VFP3 since the compare
operation can signal this case with the v flag.  Use cmp instead
of tst in the fast compilers since tst leaves the v flag unchanged
and thus can only work by accident on non-equality comparisons.
Review URL: http://codereview.chromium.org/551048

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3625 ce2b1a6d-e550-0410-aec6-3dcde31c8c00