Fix GLFW runtime platform detection

[M374LX]

Fixes #3850

In order to allow all of GLFW's source files to be combined into one, as done by rglfw.c, this PR modifies the bundled GLFW by renaming the functions that share the same name in different platforms. Additionally, it disables GLFW's Null platform, which is not used by raylib.

It also removes the USE_WAYLAND_DISPLAY variable from the Makefile while adding GLFW_LINUX_ENABLE_WAYLAND and GLFW_LINUX_ENABLE_X11, both set to TRUE by default.

[orcmid]

It is my impression that src/external/ materials are not maintained on raylib and any changes must come from the origin project of the external dependency.

If there is to be an exception to that, I trust you confirmed that before all of the work you did.

[M374LX]

@orcmid If GLFW's developers agree to avoid functions with the same name in different platforms in a future version of the library, there will be no more need for it to be modified for raylib (related: glfw/glfw#2502 and glfw/glfw#2462).

[orcmid]

@orcmid If GLFW's developers agree to avoid functions with the same name in different platforms in a future version of the library, there will be no more need for it to be modified for raylib

@M374LX I think it is a policy for raylib that externals are not to be customized and then have to be maintained here as a fork. I don't know what @raysan5 will say about this particular complicated case.

Do you see an alternative approach that would overcome the difficulty for raylib without touching src/external?

[raysan5]

@M374LX @orcmid I try to avoid customizing external libraries for raylib but unfortunately it was also done in the past with other external libraries (sinfl, jar_mod, jar_xm, vox_loader). I think this is a quite special case and considering that GLFW is bundled into raylib and a related issue has already been opened in GLFW repos, I can consider merging it.

Just waiting a bit for GLFW response on the topic. The only issue I see is the need to review it again after next GLFW release, but it can take some time.

[raysan5]

@M374LX thanks for the improvements!

[ProIcons]

This breaks the zig build on linux.