QPostEventList: de-inline addEvent()

While in a private header, it did manage to place QList<QPostEvent>
operations near the top spots of all Qt template instantiations in a
QtWidgets build.

Task-number: QTBUG-97601
Change-Id: I4fa1972b8764b71ad0559633131e7e44b3d4ae6a
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
(cherry picked from commit 1a030f6609ad6a9bbc1253e9e2d5efb198dc5998)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

src/corelib/thread/qthread.cpp

@@ -18,6 +18,29 @@
 
 QT_BEGIN_NAMESPACE
 
+/*
+    QPostEventList
+*/
+
+void QPostEventList::addEvent(const QPostEvent &ev)
+{
+    int priority = ev.priority;
+    if (isEmpty() ||
+            constLast().priority >= priority ||
+            insertionOffset >= size()) {
+        // optimization: we can simply append if the last event in
+        // the queue has higher or equal priority
+        append(ev);
+    } else {
+        // insert event in descending priority order, using upper
+        // bound for a given priority (to ensure proper ordering
+        // of events with the same priority)
+        QPostEventList::iterator at = std::upper_bound(begin() + insertionOffset, end(), ev);
+        insert(at, ev);
+    }
+}
+
+
 /*
   QThreadData
 */

src/corelib/thread/qthread_p.h

@@ -73,23 +73,7 @@ public:
 
     inline QPostEventList() : QList<QPostEvent>(), recursion(0), startOffset(0), insertionOffset(0) { }
 
-    void addEvent(const QPostEvent &ev)
-    {
-        int priority = ev.priority;
-        if (isEmpty() ||
-            constLast().priority >= priority ||
-            insertionOffset >= size()) {
-            // optimization: we can simply append if the last event in
-            // the queue has higher or equal priority
-            append(ev);
-        } else {
-            // insert event in descending priority order, using upper
-            // bound for a given priority (to ensure proper ordering
-            // of events with the same priority)
-            QPostEventList::iterator at = std::upper_bound(begin() + insertionOffset, end(), ev);
-            insert(at, ev);
-        }
-    }
+    void addEvent(const QPostEvent &ev);
 
 private:
     //hides because they do not keep that list sorted. addEvent must be used