[llvm] [LV] Narrow type of WidestIndTy (NFC) (PR #128173)

[David Sherwood via llvm-commits]

https://github.com/david-arm commented:

When I originally looked at this PR I was a bit confused because I'm used to the terminology of narrowing in C and C++ to mean choosing a narrower (smaller) type, i.e. one with fewer bits. Then I realised what you mean by "narrowing" here is choosing a type in the inheritance tree with fewer possible derived instances.

This is just a suggestion, but how about clarifying this a bit more in the title with something like "[LV] Restrict widest induction type to be IntegerType [NFC]"?

https://github.com/llvm/llvm-project/pull/128173