This reverts commit r214981.
I'm not sure what I was thinking when I wrote this. Testing with MSVC
shows that this function is mangled to '@f@8':
int __fastcall f(int a, int b);
llvm-svn: 220492
Otherwise we can end up with an argument frame size that is not a
multiple of stack slot size, which is very awkward.
This fixes PR20547, which was a bug in x86_64 Sys V vararg handling.
However, it's much easier to test this with x86 callee-cleanup
functions, which previously ended in "retl $6" instead of "retl $8".
This does affect behavior of all backends, but it presumably fixes the
same bug in all of them.
llvm-svn: 214980