Be more GCC-friendly with attributes
authorpfg <pfg@FreeBSD.org>
Fri, 28 Aug 2015 14:06:28 +0000 (14:06 +0000)
committerpfg <pfg@FreeBSD.org>
Fri, 28 Aug 2015 14:06:28 +0000 (14:06 +0000)
commit1b6f34126ead11e8584b6afc9e4dfeee68bb7a90
treed46a8b889cd3ece4872c72f45928f071c78408c2
parent6a6ecc2475486cfbe02473a560f23b626f3777e3
Be more GCC-friendly with attributes

Being clang the default compiler, we were always giving precedence to
the __has_attribute check. Unfortunately clang generally doesn't support
the new attributes (alloc_size was briefly supported and then reverted)
so we were always doing both checks. Give the precedence to GCC as that is
the working case now.

Do the same for  __has_builtin() for consistency.
sys/sys/cdefs.h