[RISCV] Add more test cases for (sub C, (setcc x, y, eq/neq)) -> (add C-1,...

[RISCV] Add more test cases for (sub C, (setcc x, y, eq/neq)) -> (add C-1, (setcc x, y, neq/eq)). NFC

In these test cases we do the transform, but the immediate is too
large to form an ADDI so it didn't save any instructions.

If the constant is opaque or has additional users we shouldn't do
the transform if it doesn't form an ADDI.