[clang] [clang][PAC] Disallow -pedantic-errors in conjunction with pointer au… (PR #153503)

[Oliver Hunt via cfe-commits]

ojhunt wrote:

@AaronBallman if we can take https://github.com/llvm/llvm-project/pull/153506 then this can be closed

https://github.com/llvm/llvm-project/pull/153503