Removed bogus ASSERTs from Intel macro assemblers.

Added a debug mode generated code assert to allocation code.
Review URL: http://codereview.chromium.org/199044

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2837 ce2b1a6d-e550-0410-aec6-3dcde31c8c00