Add lowering support for llvm.experimental.deoptimize

Summary:
Only adds support for "naked" calls to llvm.experimental.deoptimize.
Support for round-tripping through RewriteStatepointsForGC will come
as a separate patch (should be simpler than this one).

Reviewers: reames

Subscribers: sanjoy, mcrosier, llvm-commits

Differential Revision: http://reviews.llvm.org/D18429

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@264329 91177308-0d34-0410-b5e6-96231b3b80d8
7 files changed