Designer/CppTools: Fix flaky test_gotoslot_withoutProject

The document was not always updated in time.

Change-Id: Iac89985d39a8784e3cbf63dfd42b1c5150775068
Reviewed-by: Christian Stenger <christian.stenger@digia.com>

src/plugins/cpptools/cpptoolseditorsupport.cpp

@@ -308,6 +308,11 @@ void CppEditorSupport::updateDocumentNow()
     }
 }
 
+bool CppEditorSupport::isUpdatingDocument()
+{
+    return m_updateDocumentTimer->isActive() || m_documentParser.isRunning();
+}
+
 void CppEditorSupport::onDocumentUpdated(Document::Ptr doc)
 {
     if (doc.isNull())