Support Darwin ABI for PowerPC

[barracuda156]

The following source fails to compile: https://github.com/rust-lang/stacker/blob/bc775cf3ed3f16835c10e3951272bb2c8d1f8202/psm/src/arch/powerpc32.s

We need separate ones for ppc and ppc64 on macOS.

[nagisa]

Fails to compile how? Anyway, contributions welcome.

[barracuda156]

Assembler syntax is invalid for Darwin: cfi directives are not supported, registers should be prefixed (as opposed to just numbers), etc. It gonna fail with invalid input and/or unrecognized directive.

[workingjubilee]

CFI directives are not supported

...is it just impossible to debug assembly code on PowerPC Darwin???

[barracuda156]

@workingjubilee I’m not an expert in debugging, but Apple gdb works.