This patch fixes PR13626 by providing i128 support in the return
calling convention.  128-bit integers are now properly returned
in GPR3 and GPR4 on PowerPC.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172745 91177308-0d34-0410-b5e6-96231b3b80d8