detect when we can convert a new/delete sequence on a local variable to
use std::unique_ptr

Change-Id: Iecae4e4197eccdfacfce2eed39aa4a69e4a660bc
Reviewed-on: https://gerrit.libreoffice.org/19884Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Noel Grandin <noelgrandin@gmail.com>