[llvm] [InstCombine] Combine trunc (lshr X, BW-1) to i1 --> icmp slt X, 0 (#142593) (PR #143846)

[Simon Pilgrim via llvm-commits]

RKSimon wrote:

Lets ignore the flang case for now - but what happens if you regenerate logical-select.ll - do you see a diff?

https://github.com/llvm/llvm-project/pull/143846