[NVPTX] Add lowering for llvm.bitreverse.

Reviewers: tra

Subscribers: llvm-commits, jholewinski

Differential Revision: https://reviews.llvm.org/D28720

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@292301 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed