[llvm] [IndVarSimplify] Relax Restrictions on Loop Counter Stride (PR #146992)

[via llvm-commits]

buggfg wrote:

@nikic Hi, I've submitted this separate PR to relax the stride restrictions for loop counters in isLoopCounter(). Could you please take a look when you can? Thanks!

https://github.com/llvm/llvm-project/pull/146992