Based on @phire's idea, Inline constants are constants that can be used as imms in instructions.
This
- Adds OP_INLINECONSTANT to represent them in the IR
- Modifies the ConstProp pass to transform OP_CONSTANT to OP_INLINECONSTANT based on per-platform heuristics
- Modifies the backends to use imms
- Supported opcodes: Add, Sub, Lsl, Lsr, Asr, Ror, Rol