[illumos-Developer] [REVIEW] 1230 need support for recent gcc stdarg builtins

[Richard Lowe]

I'd like code review for:
   1230 need support for recent gcc stdarg builtins
webrev:
   http://richlowe.net/webrevs/il_1230

GCC used to use __builtin_stdarg_start() as va_start(), later, they
introduced __builtin_va_start() with an eye toward removing the
former.  In recent GCC (4.x) they actually did remove
__builtin_stdarg_start() and code built using our headers begins to
break.  This change teaches our headers about the needs of recent GCC.
 I modelled the version conditional based on the introduction of the
use of __builtin_va_start in the gcc/ginclude headers, which was in
3.3.


-- Rich