cc in v7

I have limited experience with cc in v7, but even this kind of experience makes me giving up on it. Besides it requires old-style function declarations, the real problem is how struct fields are handled. It seems they are in a single global namespace, which means two structures may have the same field only if the offset is the same as well. An interesting side-effect is that instead of using an union of multiple similar structs, many v7 source code just use field names of random structures on a common structure. This is common for representing trees: common structure is a generic tree node structure, while multiple specialized node structs exist.

Even if cc would be ported too, it would fail to compile most of the C code that would compile fine on UNIX and rewriting the code to use unique field names is unreasonable.