Merging r278900:

Merging r278900:
------------------------------------------------------------------------
r278900 | cycheng | 2016-08-16 20:17:44 -0700 (Tue, 16 Aug 2016) | 12 lines

[ppc64] Don't apply sibling call optimization if callee has any byval arg

This is a quick work around, because in some cases, e.g. caller's stack
size > callee's stack size, we are still able to apply sibling call
optimization even callee has any byval arg.

This patch fix: https://llvm.org/bugs/show_bug.cgi?id=28328

Reviewers: hfinkel kbarton nemanjai amehsan
Subscribers: hans, tjablin

https://reviews.llvm.org/D23441
------------------------------------------------------------------------

git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_39@278990 91177308-0d34-0410-b5e6-96231b3b80d8