[GlobalISel] Reporting rules covered as part of the InstructionSelect's debug-only printing

The main goal of this change is to make it much easier to track which
rules are actually covered by Testgen'erated regression tests.

Reviewers: aemerson, dsanders

Differential Revision: https://reviews.llvm.org/D46095


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@330988 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed