[llvm] [DA] Remove `DependenceInfo::removeMatchingExtensions` (PR #171809)

[Ryotaro Kasuga via llvm-commits]

kasuga-fj wrote:

Thanks for your review.

> I am a bit surprised this does not affect any test

There are several functions whose purpose or rationale is unclear in DA...

https://github.com/llvm/llvm-project/pull/171809