(CPP_PREDEFINES): Update GCC_NEW_VARARGS comment.

From-SVN: r6950

gcc/config/sparc/sparc.h

@@ -74,10 +74,8 @@ the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
 
 /* Names to predefine in the preprocessor for this target machine.  */
 
-/* The GCC_NEW_VARARGS macro is so that old versions of gcc can compile
-   new versions, which have an incompatible va-sparc.h file.  This matters
-   because gcc does "gvarargs.h" instead of <varargs.h>, and thus gets the
-   wrong varargs file when it is compiled with a different version of gcc.  */
+/* ??? The GCC_NEW_VARARGS macro is now obsolete, because gcc always uses
+   the right varags.h file when bootstrapping.  */
 
 #define CPP_PREDEFINES \
   "-Dsparc -Dsun -Dunix -D__GCC_NEW_VARARGS__ \