Which is relatively inconsequential as long as there's a clear boundary between things that can be manipulated by a user and the C code.

It'd be better if it wasn't C at all, sure, but, from a security perspective I'd take a language with a C runtime over a language where code has to be carefully written in a memory-safe manner any day.

GCC is written in C/C++. I don't think any of the compilers are dogfooding their language because its supposed to be reusing infrastructure.

I'd hope an LLVM compiler for a language would eventually be dogfooded, though.