std.debug: split up Mach-O debug info handling

Like ELF, we now have `std.debug.MachOFile` for the host-independent
parts, and `std.debug.SelfInfo.MachO` for logic requiring the file to
correspond to the running program.
0caca625ebMatthew Lugg committed on 11/20/2025, 10:42:20 AMparent7b325e0
8 files changedLine totals unavailable