clang bootstraps with the integrated assembler on linux x86-64

Hello,

Just wanted to let you know that with the recent fixes clang now
bootstraps on linux x86-64 with the integrated assembler. There are
likely still fixes to be done for -g and x86-32, but MC can now handle
a fairly large C++ app :slight_smile:

Cheers,

Wow, congrats! That is a major achievement for the ELF writer!

-Chris