...of measuring loplugin performance, when gathering data with perf and all
plugins that used "Visitor" as class name were lumped together.  (Cf.
<https://whatofhow.wordpress.com/2016/06/28/plugin-flamed/>.)

Change-Id: Ie482f443faced7469528da4772e735bc2eda596d
Reviewed-on: https://gerrit.libreoffice.org/43324Reviewed-by: Stephan Bergmann <sbergman@redhat.com>
Tested-by: Stephan Bergmann <sbergman@redhat.com>