Workaround for wrong cursor annotated by Clang.
Use clang_getCursor in case of the variable used as
operator argument to get the proper cursor.
Task-number: QTCREATORBUG-20966
Change-Id: Idb195bffc2296f3fae27595cf9c43c9e6b2c5cd0
Reviewed-by: Marco Bubke <marco.bubke@qt.io>