Make QAccessible::State's equality operator a hidden friend

Reduce ADL nose.

We already have an inline default constructor calling memset, so can have
the comparison operator calling memcmp also inlined.

Task-number: QTBUG-87973
Change-Id: If8e0ae98b0c44fc3fddac7ef57c5ff021c80dad6
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>

src/gui/accessible/qaccessible.cpp

@@ -1820,12 +1820,6 @@ const char *qAccessibleEventString(QAccessible::Event event)
     return QAccessible::staticMetaObject.enumerator(eventEnum).valueToKey(event);
 }
 
-/*! \internal */
-bool operator==(const QAccessible::State &first, const QAccessible::State &second)
-{
-    return memcmp(&first, &second, sizeof(QAccessible::State)) == 0;
-}
-
 #ifndef QT_NO_DEBUG_STREAM
 /*! \internal */
 Q_GUI_EXPORT QDebug operator<<(QDebug d, const QAccessibleInterface *iface)

src/gui/accessible/qaccessible.h

@@ -217,6 +217,10 @@ public:
         State() {
             memset(this, 0, sizeof(State));
         }
+        friend inline bool operator==(const QAccessible::State &first, const QAccessible::State &second)
+        {
+            return memcmp(&first, &second, sizeof(QAccessible::State)) == 0;
+        }
     };
 
 
@@ -437,8 +441,6 @@ private:
     friend class QAccessibleCache;
 };
 
-Q_GUI_EXPORT bool operator==(const QAccessible::State &first, const QAccessible::State &second);
-
 Q_DECLARE_OPERATORS_FOR_FLAGS(QAccessible::Relation)
 
 class QAccessible2Interface;