Windows registry dumping behaves very strangely, and in hard to debug
ways - this should help in-the-field debugging of this in future.

Change-Id: Ia35d58a8be36d1b683db39ae7d2128a3ccfd10a5
Reviewed-on: https://gerrit.libreoffice.org/33992Reviewed-by: Michael Meeks <michael.meeks@collabora.com>
Tested-by: Michael Meeks <michael.meeks@collabora.com>