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

[Matt Arsenault via llvm-commits]

arsenm wrote:

We probably would be better in a state where the update_*_test checks were unified - the current state is they all have annoying divergent behaviors and bugs 

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