[llvm] [DebugInfo][IndVarSimplify] fix missing debug location updates (PR #91443)

[J. Ryan Stinnett via llvm-commits]

https://github.com/jryans commented:

Change looks correct to me overall. The pass is creating replacement instructions, so it make sense to copy over the original location.

Just a small nit in the test to fix up.

https://github.com/llvm/llvm-project/pull/91443