I found the bug with the build errors in GCC/G++ headers, Aparrently this happens all the time, because SpecC is strictly enforcing (extremely old) ANSI C compatibility. Since the GCC headers don't seem to be built around any sort of ANSI C compatibility, each Linux distro has to have it's own alternate header files. This is allowed for in the SpecC build system, but the last version they included support for was Ubuntu8. I now have to add Ubuntu16 support myself. Oh well, at least I know what the problem was - I was preparing to compile all the libc-using code in src/native with straight GCC and then link it, which will cause problems later when I need to optimize things better.