[GlobalISel] Print the matched patterns using an action.

This lets us split out PatternToMatch from the top-level RuleMatcher,
where it doesn't really belong.  That, in turn, lets us eventually
generate RuleMatchers from non-SelectionDAG sources.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@294076 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed