This PR adds [CO2](https://github.com/hkalbasi/co2) which is a language
backward compatible with C, with some Rust interop features that
compiles to Rust's MIR.
I added two compiler `co2rustc` and `co2cc`, and a tool `co2miri` which
is Miri for CO2. I added `co2cc` under C compilers, to make it possible
to view diff of assembly for a C code compiled with CO2 and clang or
gcc. `co2cc` is a CO2 frontend which accepts gcc-like flags, and can (or
at least should) compile almost every ISO compatible C23 code.
`co2rustc` accepts Rust like flags, and added under a new `CO2`
language.
Tested locally and it seems to work.
I need some help in setting up artifacts (which, if I understand
correctly, needs to happen in `infra` or `compiler-workflows`). I make
an artifact `co2-multicall` in my CI, which needs to get symlinked in
`co2cc`, `co2rustc` and `co2miri`, and it needs to run a simple project
with miri to create the miri sysroot. If you show me a similar project,
I will do the job.
Disclaimer: Written partially by LLM.
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Co-authored-by: Matt Godbolt <matt@godbolt.org>
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