Canonicalize a large number of mir tests using update_mir_test_checks

This converts a large and somewhat arbitrary set of tests to use
update_mir_test_checks. I ran the script on all of the tests I expect
to need to modify for an upcoming mir syntax change and kept the ones
that obviously didn't change the tests in ways that might make it
harder to understand.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@316137 91177308-0d34-0410-b5e6-96231b3b80d8