C++: fix findusage for member of typedefed anonymous struct

Task-number: QTCREATORBUG-11859
Task-number: QTCREATORBUG-11860
Change-Id: I7484b3b88daefbb3c76bb86a9b573e8291072872
Reviewed-by: Orgad Shaneh <orgads@gmail.com>
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@digia.com>
(cherry picked from commit 5416557a0b9247e911180a7cce4a5ed3b0c0f351)
Reviewed-by: Przemyslaw Gorszkowski <pgorszkowski@gmail.com>
Reviewed-by: Eike Ziller <eike.ziller@digia.com>
C++: nested class with enclosing template class

The parent of instantiation of nested class of template class
should be the instantiation of enclosing template class.

Task-number: QTCREATORBUG-11752
Change-Id: I8875c738848b85731f5ea88a60da190b4b0ad18f
Reviewed-by: Orgad Shaneh <orgads@gmail.com>
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@digia.com>
Reviewed-by: Eike Ziller <eike.ziller@digia.com>