[smaudet]

You mentioned a runtime though.

Debating whether some language feature can exist on an mcu is somewhat unrelated - the point was about code size bloat not whether you can fake one instruction set with another...

You can fake e.g. multiply with a for loop and an add instruction (1 or 2 cycles) but that will run orders of magnitude slower than a 2 or 3 clock cycle multiply instruction...

So the point about osx arch is not really addressed, if you have runtime that cannot be easily ported or osx cpu arch which produces prohibitive instruction sets it doesn't matter if gcc can target an old version of objective C, it is, as stated, not that simple.