Fix some usage of global scope operator ::

git-svn-id: https://swig.svn.sourceforge.net/svnroot/swig/trunk@11719 626c5289-ae23-0410-ae9c-e8d60b6d4f22

Examples/test-suite/valuewrapper_const.i

@@ -24,6 +24,12 @@ public:
   const B GetBconst() const {
         return b;
   }
+  ::B GetBGlobalQualifier() {
+        return b;
+  }
+  const ::B GetBconstGlobalGlobalQualifier() const {
+        return b;
+  }
 }; 
 
 %}