[Bug sanitizer/58994] asan.exp regressions on x86_64 darwin at -m64 but not -m32 at r204372

[howarth at nitro dot med.uc.edu]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58994

--- Comment #18 from Jack Howarth <howarth at nitro dot med.uc.edu> ---
Created attachment 31212
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=31212&action=edit
fix from llvm svn