[PM] Add devirtualization-based iteration utility into the new PM's
default pipeline.

A clang with this patch built with ASan and asserts can build all of the
test-suite as well, so it seems to not uncover any latent problems.

Differential Revision: https://reviews.llvm.org/D29853

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@294888 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed