Implement get_filesystem_type on macOS and Linux.

[bruvzg]

Should fix #106384

Note: there is the same function on Linux and BSDs, but returned data (and used header) seems to be different, and Linux version only contain magic numbers for the file system types.

[akien-mga]

So I assume the same bug as #106384 might be reproducible on Linux?

[bruvzg]

So I assume the same bug as #106384 might be reproducible on Linux?

Probably yes it seems to be a generic limitation of exFAT (#28467), but detecting exFAT/FAT will require adding a hardcoded list of magic numbers and likely a dedicated implementation for each BSD flavor. I'll check it later.

[akien-mga]

I think if we support Linux and not the various BSDs for this niche scenario, it's probably fine.

[bruvzg]

Added Linux version as well, tested to detect exFAT, FAT32, and genetic FS like EXT and BTRFS. The list is copy-pasted from the header. But it seems to not work with FUSE (return generic FUSE type).

[Calinou]

Tested locally on macOS, it works as expected. Code looks good to me.

func _ready():
	var da = DirAccess.open("res://")
	print(da.get_filesystem_type())
	print(da.is_case_sensitive("res://"))

Prints:

APFS
false

[Repiteo]

Thanks!