Ahaggar: add more node types

* Currently these are commented

Signed-off-by: Djalal Harouni <tixxdz@opendz.org>
Ahaggar: add the LABEL_EXPR node walker

Signed-off-by: Djalal Harouni <tixxdz@opendz.org>
Ahaggar: call the LABEL_EXPR walker

Signed-off-by: Djalal Harouni <tixxdz@opendz.org>