[Power9] Add __float128 support for compare operations

Added handling for the select f128.

Differential Revision: https://reviews.llvm.org/D48294

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@336548 91177308-0d34-0410-b5e6-96231b3b80d8
4 files changed