[llvm] [DAG] SelectionDAG.computeKnownBits - add NSW/NUW flags support to ISD::SHL handling (PR #89877)

[Simon Pilgrim via llvm-commits]

https://github.com/RKSimon requested changes to this pull request.

According to the CI you need to regenerate fold-int-pow2-with-fmul-or-fdiv.ll and known-never-zero.ll

https://github.com/llvm/llvm-project/pull/89877