Add raylib.umi building

[RobLoach]

Fixes #11

[RobLoach]

@marekmaskarinec I'm unsure of this approach. Since we're exporting the raylib functions as the same name, we end up with conflicts on the exported names. Hopefully having the export name changed with a pragma call fixes this.

I tried testing, and am getting....

  umka-test ./umka core_basic_window.um
INFO: Initializing raylib 4.2
INFO: Supported raylib modules:
INFO:     > rcore:..... loaded (mandatory)
INFO:     > rlgl:...... loaded (mandatory)
INFO:     > rshapes:... loaded (optional)
INFO:     > rtextures:. loaded (optional)
INFO:     > rtext:..... loaded (optional)
INFO:     > rmodels:... loaded (optional)
INFO:     > raudio:.... loaded (optional)
umka: raylib-src/src/external/glfw/src/window.c:163: glfwCreateWindow: Assertion `width >= 0' failed.
fish: Job 1, './umka -warn core_basic_window.…' terminated by signal SIGABRT (Abort)

So there's definitely something wrong with it.

[marekmaskarinec]

From experience, I advice against using raw bindings to functions without umka wrappers. It can save you lot of work and make the API easier to use. You can look at tophat as an example (although src/bindings.c is currently bit of a mess).

[RobLoach]

Thanks! I have the Umka wrapper functions in there. umkaInitWindow wraps InitWindow, for instance. The problem is that building the .umi file, in the Umka script, if you have...

import "raylib.um"

fn main() {
  raylib.InitWindow(640, 480, "Hello")
  raylib.CloseWindow()
}

Umka will call InitWindow() instead of umkaInitWindow(). My hope is to use the compiler to rename the symbols in the .umi file.

As a side-note, I really like what you did with Tophat! Definitely going a really neat direction with it 👍