[llvm] [IndVarSimplify] Remove sinkunusedInvariants (PR #169250)

[Vigneshwar Jayakumar via llvm-commits]

VigneshwarJ wrote:

The above mentioned PR #157559 is reverted due to increased stack size and stack overflow when the stack size is very low. This was due to way the MSSAU was updated. I have a fix for that, but there were issues raised for performance regression with that change. So I wanted to see if removing this optimization would be a good way. Else I will raise a PR again for the #157559 again with those fixes.

https://github.com/llvm/llvm-project/pull/169250