Avoid both virtual and override on destructors

Destructors don't need to be declared virtual when the destructor from
the parent class is already declared virtual.

Additionally, this removes the last usage of Q_DECL_OVERRIDE.

Pick-to: 6.4
Change-Id: I7d43f5d5fbb1423319adde04d4994ada9daab6b1
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

src/qml/jit/qv4baselinejit_p.h

@@ -34,7 +34,7 @@ class BaselineJIT final: public Moth::ByteCodeHandler
 {
 public:
     BaselineJIT(QV4::Function *);
-    virtual ~BaselineJIT() Q_DECL_OVERRIDE;
+    ~BaselineJIT() override;
 
     void generate();
 

src/qml/jsruntime/qv4promiseobject_p.h

@@ -34,7 +34,7 @@ class ReactionHandler : public QObject
 
 public:
     ReactionHandler(QObject *parent = nullptr);
-    virtual ~ReactionHandler() override;
+    ~ReactionHandler() override;
 
     void addReaction(ExecutionEngine *e, const Value *reaction, const Value *value);
     void addResolveThenable(ExecutionEngine *e, const PromiseObject *promise, const Object *thenable, const FunctionObject *then);

src/qmldebug/qqmlprofilerclient_p_p.h

@@ -43,7 +43,7 @@ public:
     {
     }
 
-    virtual ~QQmlProfilerClientPrivate() override;
+    ~QQmlProfilerClientPrivate() override;
 
     void sendRecordingStatus(int engineId);
     bool updateFeatures(ProfileFeature feature);