[llvm] [SLP]Do extra analysis int minbitwidth if some checks return false. (PR #84363)

[Martin Storsjö via llvm-commits]

mstorsjo wrote:

> Fixed in [81d9ed6](https://github.com/llvm/llvm-project/commit/81d9ed605b126d163f2f1cc226c639f1dfdc5224)

Thanks - from a quick rerun it seems like all these cases are fixed now, and large parts of my builds pass (knowing conclusively takes much longer though).

https://github.com/llvm/llvm-project/pull/84363