[ValueTracking] Compute knownbits from `(icmp upred (add/sub nuw X, Y), C)`

`(icmp ule/ult (add nuw X, Y), C)` implies both `(icmp ule/ult X, C)` and
`(icmp ule/ult Y, C)`. We can use this to deduce leading zeros in `X`/`Y`.

`(icmp uge/ugt (sub nuw X, Y), C)` implies `(icmp uge/uge X, C)` . We
can use this to deduce leading ones in `X`.

Proofs: https://alive2.llvm.org/ce/z/sc5k22

Closes #87180