control unnecessary clang warnings

Utility/ChangeLog

+
+2012-08-16  L. Garren  <garren@fnal.gov>
+
+	* Utility/memory.h: use clang pragma
+
 ==============================
 09.07.12 Release CLHEP-2.1.2.4
 ==============================

Utility/Utility/memory.h

@@ -30,6 +30,10 @@
 //
 // ======================================================================
 
+#ifdef __clang__
+  #pragma clang diagnostic push
+  #pragma clang diagnostic ignored "-Wdelete-non-virtual-dtor"
+#endif
 
 #include "CLHEP/Utility/defs.h"
 #include "CLHEP/Utility/noncopyable.h"
@@ -1651,4 +1655,8 @@ public:  // actually private, but avoids compiler template friendship issues
   }
 };  // enable_shared_from_this2<>
 
+#ifdef __clang__
+  #pragma clang diagnostic pop
+#endif
+
 #endif  // 0