[llvm] [IR] Add nowrap flags for trunc instruction (PR #85592)

[Matt Arsenault via llvm-commits]

arsenm wrote:

> > > * [ ]    Add the support for dropping nsw/nuw flags to `llvm-reduce`
> > 
> > 
> > I've already implemented this but haven't had working internet to push it
> 
> Ping?

This was fc9a5076c31139878da2fa12ef16090a58d55782

https://github.com/llvm/llvm-project/pull/85592