Add a regression test for x86-64 red zone usage.
; RUN: llvm-as < %s | llc -march=x86-64 > %t
; RUN: not grep subq %t
; RUN: not grep addq %t
; RUN: grep {\\-4(%%rsp)} %t | count 2
; RUN: llvm-as < %s | llc -march=x86-64 -disable-red-zone > %t
; RUN: grep subq %t | count 1
; RUN: grep addq %t | count 1

define x86_fp80 @f0(float %f) nounwind readnone {
entry:
	%0 = fpext float %f to x86_fp80		; <x86_fp80> [#uses=1]
	ret x86_fp80 %0
}