Fix testcases whose variables are invalid. I'm working on a patch that
adds `Verifier` checks for `MDLocalVariable` (and `MDGlobalVariable`),
and these failed because:
- `scope:` fields need to point at `MDLocalScope` and can't be null.
- `file:` fields need to point at `MDFile`.
- `inlinedAt:` fields need to point at `MDLocation`.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233349 91177308-0d34-0410-b5e6-96231b3b80d8