[x86] Fix register constraints for multiply high and modulus.

R=jarin@chromium.org
TEST=mjsunit/compiler/regress-register-allocator2

Review URL: https://codereview.chromium.org/697053002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@25054 ce2b1a6d-e550-0410-aec6-3dcde31c8c00