Clang: Make diagnostic tooltips consistent

Fix that triggering a diagnostic tooltip from the diagnostic
location/range itself (underlined text) did not show the icon on the
left and the actions/toolbuttons on the right in the tooltip.

Instead of showing the tooltip content itself, request the tooltip for
the corresponding text mark to get the extra decoration and actions.

Change-Id: I5e94aca117a761f7a798d4f4b33db6e386e54d84
Reviewed-by: David Schulz <david.schulz@qt.io>
Reviewed-by: Ivan Donchevskii <ivan.donchevskii@qt.io>

src/plugins/texteditor/texteditor.cpp

@@ -3555,6 +3555,13 @@ QPoint TextEditorWidget::toolTipPosition(const QTextCursor &c) const
     return cursorPos + QPoint(d->m_extraArea->width(), HostOsInfo::isWindowsHost() ? -24 : -16);
 }
 
+void TextEditorWidget::showTextMarksToolTip(const QPoint &pos,
+                                            const TextMarks &marks,
+                                            const TextMark *mainTextMark) const
+{
+    d->showTextMarksToolTip(pos, marks, mainTextMark);
+}
+
 void TextEditorWidgetPrivate::processTooltipRequest(const QTextCursor &c)
 {
     const QPoint toolTipPoint = q->toolTipPosition(c);