[svn-r8934] Purpose:

Improvement

Description:
Removed "-D__GNUC__" which was a patch for previous version.
It is no longer needed.
Also moved the debug flags "-w2 and -Wall" to DEBUG_CXXFLAGS
so that they are used for debug mode only.
Also adjust CXXFLAGS setting so that -std=c99 is added only
if user has not preset CXXFLAGS.  This allows users the option
of not using it.

Platforms tested:
Tested in tg-NCSA only since that is the only ia64 platform
around.

Misc. update:

c++/config/ia64-linux-gnu

@@ -17,8 +17,9 @@ case $CXX_BASENAME in
 	;;
 
     *)
-	CXXFLAGS="$CXXFLAGS -std=c99 -w2 -Wall -D__GNUC__"
-	DEBUG_CXXFLAGS="-g"
+	# Default to C99 standard.
+	CXXFLAGS="${CXXFLAGS:--std=c99}"
+	DEBUG_CXXFLAGS="-g -w2 -Wall"
 	DEBUG_CPPFLAGS=
 	PROD_CXXFLAGS=""     #Default optimization O2 is used
 	PROD_CPPFLAGS=