[RISCV] Fold special case (xor (setcc constant, y, setlt), 1) -> (setcc y, constant + 1, setlt)

Improve D151719.
(xor (setcc constant, y, setlt), 1) -> (setcc y, constant + 1, setlt)
https://alive2.llvm.org/ce/z/BZNEia

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D152128