[llvm] [Reland][ValueTracking] Improve Bitcast handling to match SDAG (PR #145223)

[Simon Pilgrim via llvm-commits]

RKSimon wrote:

You're trying to test that knownbits the demanded elts across the full width of the source are being cjecked and not just the SubScale

https://github.com/llvm/llvm-project/pull/145223