#include <stdio.h>

on x86 gives the following trace with GCC's preprocessed output:

# 1 "main.c"
# 1 "<built-in>"
# 1 "<command line>"
# 1 "main.c"
# 10 "main.c"
# 1 "/usr/include/stdio.h" 1 3 4
# 40 "/usr/include/stdio.h" 3 4
# 1 "/usr/include/sys/ansi.h" 1 3 4
# 42 "/usr/include/sys/ansi.h" 3 4
# 1 "/usr/include/machine/int_types.h" 1 3 4
# 43 "/usr/include/machine/int_types.h" 3 4
typedef __signed char __int8_t;

I'm writing an ANSI C compiler front end, and have yet to implement
GCC extensions.  It shows exactly the same header trace as
above, with __signed.  I believe it is NetBSD's intent to have their
headers compilable with compilers other than GCC?

Neil.