But that's an interesting point. Why is there a C++ compiler in the base? Do I find a long discussion on the FreeBSD list about whether it should have a C++ compiler? If not, why not?
Rewrite everything C++ is not a small undertaking with (maybe?) not allot plus-sides, and even then you still need C++ because of LLVM. LLVM and GCC are both C++, and you have to compile the Compiler (self-hosting), and even if your a 100% Rust or C OS, you still need C++ because of LLVM/GCC....well if you want a modern compiler ;)
Not important, you have to compile your Compiler fini, btw for Linux (just the Kernel) you need Perl ;)
I am guessing that performance of current standalone C compiler is not as good as the one produced by compiler suit.
Following the conversation thread, rust also use llvm under the hood, but a customized one. Which would force the base system to have two versions of llvm.