This is a very large diff, but most of it comes from test files and
output.
This PR ads partial support for the following Stage3D shader features:
* Normal (square), rectangle, and cube textures
* Varying and temporary registers
* Lots of opcodes
The combination of these allows us to get a raytracing program
fully working in Ruffle. I've included it as image test.
Currently, this test is very slow (about 90 seconds on my machine),
as the code I'm using (https://github.com/saharan/OGSL) includes
its own shader language and compiler. THe raytracing demo
first compiles its own shader language to AGAL, and then starts
rendering the scene.
Limitations:
* Many opcodes are still unimplemented
* Most non-default texture options (e.g. mipmaps) are not implemented
Aaron Hill