[AArch64] Fix comparison peephole opt with non-0/1 immediate (PR51476)

This is a non-intrusive fix for
https://bugs.llvm.org/show_bug.cgi?id=51476 intended for backport
to the 13.x release branch. It expands on the current hack by
distinguishing between CmpValue of 0, 1 and 2, where 0 and 1 have
the obvious meaning and 2 means "anything else". The new optimization
from D98564 should only be performed for CmpValue of 0 or 1.

For main, I think we should switch the analyzeCompare() and
optimizeCompare() APIs to use int64_t instead of int, which is in
line with MachineOperand's notion of an immediate, and avoids this
problem altogether.

Differential Revision: https://reviews.llvm.org/D108076