(this is a corrected patch)
Calling _chkstk is required on ELF as well as COFF on Windows. Without
_chkstk, functions requiring large stack crash in initialization code.
Previous code tested for COFF format but not Mach-O and this patch modifies
the code to test for Windows OS (both Windows target and MingW target)
but not Mach-O object format: Looks like macho environment was used to
build some EFI code.
Credits to Andrew MacPherson.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193289
91177308-0d34-0410-b5e6-
96231b3b80d8