GLAD support

[AGraber]

Support GLAD as an alternative OpenGL loader to use for platforms where GLEW isn't available (eg. Switch).

Let the system provide its own glad path as well for platform specific stuff when building

[Deleted user]

There's no sdl for switch?

[AGraber]

Switch does support SDL, but SDL is irrelevant. GLAD and GLEW are both OpenGL function loaders.

GLAD might not be necessary though since I'm now looking into porting GLEW into the switch (aarch64 + must use egl for loading). I'll close this issue if that's the case. I've been trying to avoid this so I can focus on the port itself, since both provide the same functionality and changing them is a matter of changing some lines

[fjtrujy]

Good idea, you can start adapting this library to work with the PS2.