Add pthread_self function prototype and make it speculatable.

Summary: This allows pthread_self to be pulled out of a loop by LICM.

Reviewers: hfinkel, arsenm, davide

Reviewed By: davide

Subscribers: davide, wdng, llvm-commits

Differential Revision: https://reviews.llvm.org/D32782

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@303495 91177308-0d34-0410-b5e6-96231b3b80d8
5 files changed