[llvm] [ValueTracking] Enhance overflow computation for unsigned mul (PR #171568)

[Yingwei Zheng via llvm-commits]

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

LGTM. Compile time impact looks neutral: https://llvm-compile-time-tracker.com/compare.php?from=42898499310b7b105db90701b579dc1cb8c23e8b&to=6489ba123e9b956092df051bd4330a1948052bc7&stat=instructions:u

https://github.com/llvm/llvm-project/pull/171568