Zapcc Compiler

I think you have already read it in the news. But I think it needs also a place here, to remember for later times.

Ceemple Software Ltd.have published a modified clang as OpenSource for x86 Linux

So it would be a long time project, to port it to Haiku.
But the benefit you can see at

So possibly it would also be faster to compile and recompile Haiku.