[MCA] Add -summary-view option

Summary:
While that is indeed a quite interesting summary stat,
there are cases where it does not really add anything
other than consuming extra lines.

Declutters the output of D48190.

Reviewers: RKSimon, andreadb, courbet, craig.topper

Reviewed By: andreadb

Subscribers: javed.absar, gbedwell, llvm-commits

Differential Revision: https://reviews.llvm.org/D48209

llvm-svn: 334833