x86: Use {push,pop}{l,q}_cfi in more places

... plus additionally introduce {push,pop}f{l,q}_cfi. All in the
hope that the code becomes better readable this way (it gets
quite a bit smaller in any case).

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Acked-by: Alexander van Heukelum <heukelum@fastmail.fm>
LKML-Reference: <4C7FBDA40200007800013FAF@vpn.id2.novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>