QTimerInfo: re-pack the members

0148c6925e added support for qint64
intervals in the abstract dispatcher. Changing the `int` interval
to `qint64` causes padding in the QTimerInfo struct.

On X86-64:

    struct TimerInfo {
	    int                        id;                   /*     0     4 */

	    /* XXX 4 bytes hole, try to pack */

	    qint64                     interval;             /*     8     8 */
	    enum TimerType             timerType;            /*    16     4 */

	    /* XXX 4 bytes hole, try to pack */

	    struct timespec            timeout;              /*    24    16 */
	    class QObject *            obj;                  /*    40     8 */
	    class QTimerInfo * *       activateRef;          /*    48     8 */

	    /* size: 56, cachelines: 1, members: 6 */
	    /* sum members: 48, holes: 2, sum holes: 8 */
	    /* last cacheline: 56 bytes */
    };

On ARM32:

    struct TimerInfo {
	    int                        id;                   /*     0     4 */

	    /* XXX 4 bytes hole, try to pack */

	    qint64                     interval;             /*     8     8 */
	    enum TimerType             timerType;            /*    16     4 */
	    struct timespec            timeout;              /*    20     8 */
	    class QObject *            obj;                  /*    28     4 */
	    class QTimerInfo * *       activateRef;          /*    32     4 */

	    /* size: 40, cachelines: 1, members: 6 */
	    /* sum members: 32, holes: 1, sum holes: 4 */
	    /* padding: 4 */
	    /* last cacheline: 40 bytes */
    };

Change the order of the members, so we remove the padding:

    struct TimerInfo {
	    int                        id;                   /*     0     4 */
	    enum TimerType             timerType;            /*     4     4 */
	    qint64                     interval;             /*     8     8 */
	    struct timespec            timeout;              /*    16    16 */
	    class QObject *            obj;                  /*    32     8 */
	    class QTimerInfo * *       activateRef;          /*    40     8 */

	    /* size: 48, cachelines: 1, members: 6 */
	    /* last cacheline: 48 bytes */
    };

Pick-to: 6.5
Change-Id: Ia1cc56e497f87611fa411a19361f8ebb13ff1f67
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/corelib/kernel/qtimerinfo_unix_p.h

@@ -28,8 +28,8 @@ QT_BEGIN_NAMESPACE
 // internal timer info
 struct QTimerInfo {
     int id;           // - timer identifier
-    qint64 interval;     // - timer interval in milliseconds
     Qt::TimerType timerType; // - timer type
+    qint64 interval;     // - timer interval in milliseconds
     timespec timeout;  // - when to actually fire
     QObject *obj;     // - object to receive event
     QTimerInfo **activateRef; // - ref from activateTimers