Remove virtual destructors from POD toolkit types

This one's been haunting me for a couple decades.  "Make all the things
virtual!" was kind of a strategy I had for forward compatibility when I
wrote this code when I was 20 or so and didn't know better.

taglib/fileref.cpp

@@ -299,7 +299,7 @@ public:
     file(nullptr),
     stream(nullptr) {}
 
-  ~FileRefPrivate() override {
+  ~FileRefPrivate() {
     delete file;
     delete stream;
   }

taglib/toolkit/tbytevector.h

@@ -95,7 +95,7 @@ namespace TagLib {
     /*!
      * Destroys this ByteVector instance.
      */
-    virtual ~ByteVector();
+    ~ByteVector();
 
     /*!
      * Sets the data for the byte array using the first \a length bytes of \a data

taglib/toolkit/tbytevectorlist.h

@@ -50,7 +50,7 @@ namespace TagLib {
     /*!
      * Destroys this ByteVectorList instance.
      */
-    ~ByteVectorList() override;
+    ~ByteVectorList();
 
     /*!
      * Make a shallow, implicitly shared, copy of \a l.  Because this is

taglib/toolkit/tlist.h

@@ -74,7 +74,7 @@ namespace TagLib {
      * Destroys this List instance.  If auto deletion is enabled and this list
      * contains a pointer type all of the members are also deleted.
      */
-    virtual ~List();
+    ~List();
 
     /*!
      * Returns an STL style iterator to the beginning of the list.  See

taglib/toolkit/tlist.tcc

@@ -69,7 +69,7 @@ template <class TP> class List<T>::ListPrivate<TP *>  : public ListPrivateBase
 public:
   ListPrivate() : ListPrivateBase() {}
   ListPrivate(const std::list<TP *> &l) : ListPrivateBase(), list(l) {}
-  ~ListPrivate() override {
+  ~ListPrivate() {
     clear();
   }
   void clear() {

taglib/toolkit/tmap.h

@@ -76,7 +76,7 @@ namespace TagLib {
     /*!
      * Destroys this instance of the Map.
      */
-    virtual ~Map();
+    ~Map();
 
     /*!
      * Returns an STL style iterator to the beginning of the map.  See

taglib/toolkit/tpropertymap.h

@@ -133,7 +133,7 @@ namespace TagLib {
      */
     PropertyMap(const SimplePropertyMap &m);
 
-    ~PropertyMap() override;
+    ~PropertyMap();
 
     /*!
      * Inserts \a values under \a key in the map.  If \a key already exists,

taglib/toolkit/trefcounter.h

@@ -43,7 +43,7 @@ namespace TagLib
   {
   public:
     RefCounter();
-    virtual ~RefCounter();
+    ~RefCounter();
 
     void ref();
     bool deref();

taglib/toolkit/tstring.h

@@ -185,7 +185,7 @@ namespace TagLib {
     /*!
      * Destroys this String instance.
      */
-    virtual ~String();
+    ~String();
 
     /*!
      * Returns a deep copy of this String as an std::string.  The returned string

taglib/toolkit/tstringlist.h

@@ -74,7 +74,7 @@ namespace TagLib {
     /*!
      * Destroys this StringList instance.
      */
-    ~StringList() override;
+    ~StringList();
 
     /*!
      * Concatenate the list of strings into one string separated by \a separator.