QmlJS: Fix completion for slots.

When reading the xml file describing the Qml types, we incorrectly
classified all functions as methods. They should be slots, since
otherwise qmldump couldn't have dumped them in the first place.

Task-number: QTCREATORBUG-1755
Reviewed-by: Erik Verbruggen

src/libs/qmljs/qmljsinterpreter.cpp

@@ -694,6 +694,7 @@ private:
         }
 
         FakeMetaMethod method(name, type);
+        method.setMethodType(FakeMetaMethod::Slot);
 
         while (_xml.readNextStartElement()) {
             if (_xml.name() == QLatin1String("param")) {