Metaprogram for converting Jai functions to shaders.

To build examples and run all tests:

jai -quiet build.jai - -run_tests

The metaprogram in Jai_To_Shader.jai watches compiler messages and sees Jai functions noted with @compute_shader or @fragment_shader or @vertex_shader. It then emits string constants into the build which can be retrieved with the get_transpiled function.