0024607: Fix some GCC compiler warnings

- enumeration value not handled in switch in Aspect_ColorScale.cxx, TNaming_DeltaOnModification.cxx
- comparison between signed and unsigned integer expressions in NIS_Triangulated.cxx, OSD_MAllocHook.cxx, RWStl.cxx
- static function defined or declared but not used in OpenGl_Workspace_2.cxx, ProjLib_ComputeApprox.cxx

src/Aspect/Aspect_ColorScale.cxx

@@ -508,6 +508,9 @@ void Aspect_ColorScale::DrawScale( const Quantity_Color& aBgColor,
     Standard_Integer last1( i1 ), last2( i2 );
     x = X + spacer;
     switch ( labPos ) {
+    case Aspect_TOCSP_NONE:
+    case Aspect_TOCSP_LEFT:
+      break;
     case Aspect_TOCSP_CENTER:
       x += ( colorWidth - textWidth ) / 2;
       break;