sys/stdarg.h and expect compiler to provide proper builtins, defaulting
to the GCC interface. lint still has a special fallback.
Reduce abuse of _BSD_VA_LIST_ by defining __va_list by default and
derive va_list as required by standards.
include path: the normal header files now include the "SSP" ones (which one
should note are not really named right: SSP and FORTIFY_SOURCE are independent
features).
Disable USE_SSP on targets where the compiler doesn't support it at all
(mips, alpha) or it's known broken (sh3). But enable FORTIFY_SOURCE,
without SSP, on those platforms -- tested on mipsel.
(what other systems keep in libssp, we already have in libc) into libc
to match what other systems with FORTIFY_SOURCE do. Goodbye, libssp
dependency in libraries and executables. Discussed with christos and
mrg; Christos will merge the headers to get us the rest of the way to a
FORTIFY_SOURCE implementation that works as others' code expects.