QMacAutoReleasePool: unexport

We should not export non-polymorphic classes wholesale. Only export
the non-inline functions instead.

There are no implicitly-declared special member functions in this
class that could cause problems, so we don't need to delay until Qt 7.

Pick-to: 6.6
Task-number: QTBUG-104164
Change-Id: I2e98782160cccb9c0f59a68e67ffd29fec42b728
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>

src/corelib/kernel/qcore_mac_p.h

@@ -109,11 +109,11 @@ protected:
     T value;
 };
 
-class Q_CORE_EXPORT QMacAutoReleasePool
+class QMacAutoReleasePool
 {
 public:
-    QMacAutoReleasePool();
-    ~QMacAutoReleasePool();
+    Q_CORE_EXPORT QMacAutoReleasePool();
+    Q_CORE_EXPORT ~QMacAutoReleasePool();
 private:
     Q_DISABLE_COPY(QMacAutoReleasePool)
     void *pool;