[PATCH] Fix ARM AAPCS regression caused by r211898

[Renato Golin]

Hi Oliver,

ByVal is normally a big deal for performance when structures are passed as arguments, and I don't think we should disable it like that. I don't have benchmark numbers to tell if it really is worth keep it, maybe you can disable it and run some benchmarks.

All in all, this commit looks ok and if no one is against it, feel free to commit. We can leave the ByVal discussion for later.

cheers,
--renato

http://reviews.llvm.org/D4541