Summary: This fixes http://llvm.org/bugs/show_bug.cgi?id=19530.
The problem is that X86ISelLowering erroneously thought the third call
was eligible for tail call elimination.
It would have been if it's return value was actually the one returned
by the calling function, but here that is not the case and
additional values are being returned.
Test Plan: Test case from the original bug report is included.
Reviewers: rafael
Reviewed By: rafael
Subscribers: rafael, llvm-commits
Differential Revision: http://reviews.llvm.org/D4968
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216117 91177308-0d34-0410-b5e6-96231b3b80d8
