SafepointIRVerifier port to new Pass Manager

Straightforward port of StatepointIRVerifier pass to new Pass Manager framework.

Fix By: skatkov
Reviewed By: fedor.sergeev
Differential Revision: https://reviews.llvm.org/D59825

This is a re-land of r357147/r357148 with LLVM_ENABLE_MODULES build fixed.
Adding IR/SafepointIRVerifier.h into its own module.

llvm-svn: 357361