[InstSimplify] use knownbits to fold more udiv/urem

We could use knownbits on both operands for even more folds (and there are
already tests in place for that), but this is enough to recover the example
from:
https://github.com/llvm/llvm-project/issues/51934
(the tests are derived from the code in that example)

I am assuming no noticeable compile-time impact from this because udiv/urem
are rare opcodes.

Differential Revision: https://reviews.llvm.org/D116616