[llvm] [SCCP] Add support for trunc nuw range. (PR #152990)

[Mikael Holmén via llvm-commits]

mikaelholmen wrote:

> will look at this latter but a bit confused what you mean with
> 
> > where %j.03 is first -20 and then -19
> 
> as the trunc is nuw the variable %j.03 can not have negative values as the trunc will result in poison then see https://llvm.org/docs/LangRef.html#trunc-to-instruction

Ok, so that's where the input is already broken becuase the input to it is 0xffec (-20).
Then I'll go hunt down whoever added the nuw to the trunc.

Thanks and sorry for the noise here.

https://github.com/llvm/llvm-project/pull/152990