[AArch64] Peephole rule to remove redundant cmp after cset.

Comparisons to zero or one after cset instructions can be safely
removed in examples like:

cset w9, eq          cset w9, eq
cmp  w9, #1   --->   <removed>
b.ne    .L1          b.ne    .L1

cset w9, eq          cset w9, eq
cmp  w9, #0   --->   <removed>
b.ne    .L1          b.eq    .L1

Peephole optimization to detect suitable cases and get rid of that
comparisons added.

Differential Revision: https://reviews.llvm.org/D98564