* Fix incorrect signedness in disassembly of umull/mull on ARM.
* Fix incorrect register order in disassembly of umull/mull.
* Fix incorrect assembly of umull on ARM.
* Remove retroactively obsoleted restriction on choice of
  registers in mul instructions on ARM.
Review URL: http://codereview.chromium.org/150002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2292 ce2b1a6d-e550-0410-aec6-3dcde31c8c00