Use -Wno-ctor-dtor-privacy for g++ builds.

Bug #113192 r=dbaron

configure.in

@@ -635,7 +635,7 @@ fi
 
 if test "$GNU_CXX"; then
     # Turn on GNU specific features
-    _WARNINGS_CXXFLAGS="${_WARNINGS_CXXFLAGS} -Wall -Wconversion -Wpointer-arith -Wbad-function-cast -Wcast-align -Woverloaded-virtual -Wsynth"
+    _WARNINGS_CXXFLAGS="${_WARNINGS_CXXFLAGS} -Wall -Wconversion -Wpointer-arith -Wbad-function-cast -Wcast-align -Woverloaded-virtual -Wsynth -Wno-ctor-dtor-privacy"
 
 	dnl The following warning breaks Qt
 	if test ! "$QTDIR"; then
@@ -729,7 +729,7 @@ case "$target" in
     LIBS="$LIBS -lbe"
     AC_CHECK_LIB(bind,main,LIBS="$LIBS -lbind")
     _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Wno-multichar"
-    _WARNINGS_CXXFLAGS="${_WARNINGS_CXXFLAGS} -Wno-multichar -Wno-ctor-dtor-privacy"
+    _WARNINGS_CXXFLAGS="${_WARNINGS_CXXFLAGS} -Wno-multichar"
     ;;
 
 *-bsdi*)