[RewriteStatepointsForGC] Yet more test cases for relocation

[RewriteStatepointsForGC] Yet more test cases for relocation

At this point, we should have decent coverage of the involved code.  I've got a few more test cases to cleanup and submit, but what's here is already reasonable.

I've got a collection of liveness tests which will be posted for review along with a decent liveness algorithm in the next few days.  Once those are in, the code in this file should be well tested and I can start renaming things without risk of serious breakage.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231414 91177308-0d34-0410-b5e6-96231b3b80d8