Fix:
* code completion
* follow symbols
* find usages

Task-number: QTCREATORBUG-8375
Change-Id: Ia40273fec3dead76acad4695b852a9e53065d8a7
Reviewed-by: Petar Perisin <petar.perisin@gmail.com>
Reviewed-by: Erik Verbruggen <erik.verbruggen@digia.com>