[macOS, 3.2] Add support for the Apple Silicon (ARM64) build target.

[bruvzg]

Adds support for ARM64 target on macOS (with -arch arm64 option, targets x86-64 when arch is not specified).

Same as #39788 for 3.2 branch.

Universal binary can be created in the similar manner to iOS (currently this step is not automated):

lipo -create ./bin/godot.osx.opt.tools.64 ./bin/godot.osx.opt.tools.arm64 -output ./bin/godot.osx.opt.tools.universal

[akien-mga]

Thanks!

[johnblommers]

My limited understanding is that native Apple Silicon applications need to use Metal and not OpenGL. How does Godot manage to pull this off?

[bruvzg]

My limited understanding is that native Apple Silicon applications need to use Metal and not OpenGL

Apple consider OpenGL is deprecated, but it's still available on all macOS and iOS devices.

[aaronfranke]

Should this also be backported to 3.1, 3.0, and 2.1? While backporting is not technically required to get those Godot versions to run on Apple Silicon, they would have low performance. I think this qualifies as a platform support fix.