[RFC] Rework mem_barrier() definitions in compiler.h

[Alan Coopersmith]

Matt Turner wrote:
> o is the defined(sun) checking for solaris?

Almost always - it technically means SunOS or Solaris, but Xorg has never
supported pre-Solaris versions of SunOS.   (There's still some places that
have defined(sun) && defined(SVR4) for Solaris to distinguish it from old
SunOS, but that's a bit redundant these days.   (Anyone running a 1989
kernel has to be a bit insane to think a brand new 2009 X server will
run well on it.   I've got a patch almost ready to go to drop our
pre-1999 Solaris kernel support out soon and bring the minimum supported
release up to Solaris 8.)

If you prefer __'s to seperate the namespace, you can also change it to
defined(__sun).   (The Sun compiler in strict ANSI mode only defines __sun,
not sun, and I believe gcc does the same.)

-- 
	-Alan Coopersmith-           alan.coopersmith at sun.com
	 Sun Microsystems, Inc. - X Window System Engineering