generateJumpTableForInstr :: instr -> Maybe (NatCmmTop instr),
getJumpDestBlockId :: jumpDest -> Maybe BlockId,
canShortcut :: instr -> Maybe jumpDest,
generateJumpTableForInstr :: instr -> Maybe (NatCmmTop instr),
getJumpDestBlockId :: jumpDest -> Maybe BlockId,
canShortcut :: instr -> Maybe jumpDest,