a couple more fixes to self-memory-alignment

panda/src/egg/eggAttributes.h

@@ -34,7 +34,7 @@
 //               appearances of the EggObject base class.  And making
 //               EggObject a virtual base class is just no fun.
 ////////////////////////////////////////////////////////////////////
-class EXPCL_PANDAEGG EggAttributes {
+class EXPCL_PANDAEGG EggAttributes : public MemoryBase {
 PUBLISHED:
   EggAttributes();
   EggAttributes(const EggAttributes &copy);

panda/src/express/namable.h

@@ -26,7 +26,7 @@
 //               The name is either empty or nonempty, but it is never
 //               NULL.
 ////////////////////////////////////////////////////////////////////
-class EXPCL_PANDAEXPRESS Namable {
+class EXPCL_PANDAEXPRESS Namable : public MemoryBase {
 PUBLISHED:
   INLINE Namable(const string &initial_name = "");
   INLINE Namable(const Namable &copy);

pandatool/src/dxf/dxfFile.h

@@ -36,7 +36,7 @@ static const int DXF_num_colors = 256;
 //               appropriate functions overridden (particularly
 //               DoneEntity()).
 ////////////////////////////////////////////////////////////////////
-class DXFFile {
+class DXFFile : public MemoryBase {
 public:
   DXFFile();
   virtual ~DXFFile();