zig-mos - Initial Support

Targets enabled

• m68k (experimental llvm [upstream])
• mos (llvm-mos only)

Note: targets mos-nes|mos-atari8|mos-atari2600|mos-c64 unstable (not working yet), recommended mos-freestanding.

For zig cc/zig c++ can use --ld65-path= instead of --fuse-ld= (unused flag).

Mini-doc (commands & target info)

• https://gist.github.com/kassane/4e8d485a09aaab475aa17f6ca3818fcb