[OptRemarkEmitter] Port to new PM

Summary:
The main goal is to able to start using the new OptRemarkEmitter
analysis from the LoopVectorizer.  Since the vectorizer was recently
converted to the new PM, it makes sense to convert this analysis as
well.

This pass is currently tested through the LoopDistribution pass, so I am
also porting LoopDistribution to get coverage for this analysis with the
new PM.

Reviewers: davidxl, silvas

Subscribers: llvm-commits, mzolotukhin

Differential Revision: https://reviews.llvm.org/D22436

llvm-svn: 275810