[InstCombine] Improve eq/ne by parts to handle `ult/ugt` equality pattern.

(icmp eq/ne (lshr x, C), (lshr y, C) gets optimized to `(icmp
ult/uge (xor x, y), (1 << C)`. This can cause the current equal by
parts detection to miss the high-bits as it may get optimized to the
new pattern.

This commit adds support for detecting / combining the ult/ugt
pattern.

Closes #69884