Am I understanding correctly that this is a regular C compiler used as a component of the Zig compiler chain allowing compilation of C files alongside Zig? Or does Zig generate C and therefore need a C compiler under the hood?
Looking at the documentation suggests it is the former, not the latter.
I also started reading through the Zig overview [1] and near the end of that document it says this: "Not only can Zig compile C code, but there is a very good reason to use Zig as a C compiler: Zig ships with libc."
From the doc, IIUC, compilation of header files and other C code allows Zig to do direct interop with no intermediaries. Seems useful.
I guess since you said header, you keep everything opaque and create a header for that which gets translated to Zig.