Expand C frontend to support full compilation of ANSI C standard

[andrew-johnson-4]

This would need a full rewrite of the C frontend, which is probably necessary anyways.

[andrew-johnson-4]

Parse __attribute__ and add to type signatures instead of ignoring.

[alex-s168]

It would be cool if it supported a similar amount of ISO C99 features as TCC.
Also it would be extremly awesome if I could extend it to support OpenCL C 1.2 (which is ISO C99 - some features + extensions) because I want to make a custom OpenCL implementation for a few projects.

[andrew-johnson-4]

Sure. As long as the standards don't contradict each other. This is not a conservative frontend.

[alex-s168]

I don't want to sound too needy, but a usable C frontend and integration with my compiler backend is important to me because I need it for many of my projects. I will do the integration with my compiler backend myself, but I am too inexperienced at making frontends, so it would be awesome if the C frontend would be high priority...

[andrew-johnson-4]

I think the Core is working well enough to work on this some more. I am not sure that it will be perfect coming right off the block, but there are a lot of things that I can improve on. I have some work coming in that I need to clear out, but I'll make this high priority for when I can get to it.

• extend C parser to grab full expressions
• extend C parser to grab edge cases such as multiple declarations
• etc. until a test suite of ANSI C starts passing