[clang] [Clang] Remove redundant check for scoped enums in shift operators (PR #152865)

[Timothy Choi via cfe-commits]

tinnamchoi wrote:

I prefer keeping my PRs atomic. All of my changes in that PR are necessary towards the primary goal of that PR, whereas this change wouldn't be. If I allowed myself to make refactors whenever I'm working on a feature it would introduce quite a bit of noise, which seems like a bad habit to have.

https://github.com/llvm/llvm-project/pull/152865