Unbreak ubsan developer-build

GCC 5.3's undefined-behavior sanitizer checks that the
declared type of the object is a base class of the
dynamic type of the object on each access to a member
of a class type.

It therefore requires the typeinfo for these types,
which for polymorphic types is emitted in the TU where
the vtable is emitted, too.

QFileDialogPrivate is a polymorphic non-exported class,
so this failed at link-time. Ditto for the other cases.

Fix by autotest-exporting the classs.

Also, where applicable, de-inline the dtors, so the
vtable (and typeinfo) are pinned to one TU, and the
ctor, just because it's the correct thing to do.

Change-Id: I2b7dba776282a2809c80eb2bc36440d7d698f926
Reviewed-by: Olivier Goffart (Woboq GmbH) <ogoffart@woboq.com>

src/widgets/dialogs/qfontdialog.cpp

@@ -102,6 +102,15 @@ QFontListView::QFontListView(QWidget *parent)
 static const Qt::WindowFlags DefaultWindowFlags =
         Qt::Dialog | Qt::WindowSystemMenuHint;
 
+QFontDialogPrivate::QFontDialogPrivate()
+    : writingSystem(QFontDatabase::Any), options(new QFontDialogOptions)
+{
+}
+
+QFontDialogPrivate::~QFontDialogPrivate()
+{
+}
+
 /*!
   \class QFontDialog
   \ingroup standard-dialogs

src/widgets/dialogs/qfontdialog_p.h

@@ -65,14 +65,13 @@ class QGroupBox;
 class QLabel;
 class QLineEdit;
 
-class QFontDialogPrivate : public QDialogPrivate
+class Q_AUTOTEST_EXPORT QFontDialogPrivate : public QDialogPrivate
 {
     Q_DECLARE_PUBLIC(QFontDialog)
 
 public:
-    inline QFontDialogPrivate()
-        : writingSystem(QFontDatabase::Any), options(new QFontDialogOptions)
-    { }
+    QFontDialogPrivate();
+    ~QFontDialogPrivate();
 
     QPlatformFontDialogHelper *platformFontDialogHelper() const
         { return static_cast<QPlatformFontDialogHelper *>(platformHelper()); }

src/widgets/graphicsview/qgraphicsproxywidget_p.h

@@ -52,7 +52,7 @@
 
 QT_BEGIN_NAMESPACE
 
-class QGraphicsProxyWidgetPrivate : public QGraphicsWidgetPrivate
+class Q_AUTOTEST_EXPORT QGraphicsProxyWidgetPrivate : public QGraphicsWidgetPrivate
 {
     Q_DECLARE_PUBLIC(QGraphicsProxyWidget)
 public:

src/widgets/itemviews/qlistview_p.h

@@ -293,7 +293,7 @@ private:
 
 };
 
-class QListViewPrivate: public QAbstractItemViewPrivate
+class Q_AUTOTEST_EXPORT QListViewPrivate: public QAbstractItemViewPrivate
 {
     Q_DECLARE_PUBLIC(QListView)
 public:

src/widgets/widgets/qdatetimeedit.cpp

@@ -1687,6 +1687,10 @@ QDateTimeEditPrivate::QDateTimeEditPrivate()
 #endif
 }
 
+QDateTimeEditPrivate::~QDateTimeEditPrivate()
+{
+}
+
 void QDateTimeEditPrivate::updateTimeSpec()
 {
     minimum = minimum.toDateTime().toTimeSpec(spec);

src/widgets/widgets/qdatetimeedit_p.h

@@ -62,11 +62,12 @@
 QT_BEGIN_NAMESPACE
 
 class QCalendarPopup;
-class QDateTimeEditPrivate : public QAbstractSpinBoxPrivate, public QDateTimeParser
+class Q_AUTOTEST_EXPORT QDateTimeEditPrivate : public QAbstractSpinBoxPrivate, public QDateTimeParser
 {
     Q_DECLARE_PUBLIC(QDateTimeEdit)
 public:
     QDateTimeEditPrivate();
+    ~QDateTimeEditPrivate();
 
     void init(const QVariant &var);
     void readLocaleSettings();

src/widgets/widgets/qlabel_p.h

@@ -60,7 +60,7 @@
 
 QT_BEGIN_NAMESPACE
 
-class QLabelPrivate : public QFramePrivate
+class Q_AUTOTEST_EXPORT QLabelPrivate : public QFramePrivate
 {
     Q_DECLARE_PUBLIC(QLabel)
 public: