>The problem that I have is that ld complains about unresolved __fxstat and
>__xstat symbols (e.g. in cccp.o) when bulding the stage2 compiler. When
>building the stage1 compiler the cccp.o contains only _fstat and _stat
>symbols which can be resolved by /usr/lib/libc.a. However there are no
>__fxstat or __xstat symbols in any of the libs in /usr/lib. The symbols
>sneak in when including /usr/include/sys/stat.h.

It looks like the compiler is confused about whether the target system has 
underscores or not.  On a.out systems underscores are traditionally prepended 
to C symbol names.

p.