[llvm] [GlobalISel] Add a update_givaluetracking_test_checks.py script (PR #140296)

[Alexander Richardson via llvm-commits]

https://github.com/arichardson commented:

Could this be integrated into `update_mir_test_checks.py` if we see `-passes="print<gisel-value-tracking>"` in the RUN line?

https://github.com/llvm/llvm-project/pull/140296