Use the unified syntax when generating assembly for clang. The clang 3.5
integrated assembler only accepts it.

MFC after:	1 week
Sponsored by:	ABT Systems Ltd


git-svn-id: svn+ssh://svn.freebsd.org/base/head@275564 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f