Speculative fix for xray assembler error on MachO since r349976
This .file directive wasn't doing anything on MachO, and now that's
diagnosed as an error.
.text
#if !defined(__APPLE__)
.section .text
+ .file "xray_trampoline_x86.S"
#else
.section __TEXT,__text
#endif
- .file "xray_trampoline_x86.S"
//===----------------------------------------------------------------------===//
