[llvm] [VPlan] Narrow truncates of an induction plus a constant offset (PR #226035)

[Ramkumar Ramachandra via llvm-commits]

https://github.com/artagnon approved this pull request.

This is a clear and correct improvement, and I don't have other suggestions, so LGTM, thanks. However, kindly wait on another reviewer's input as well before landing.

https://github.com/llvm/llvm-project/pull/226035