support alternative and multiple suffixes in $$resolve_depends()

this is undeniably a new feature, but it's needed for a bugfix.

Change-Id: I951a3128eb580404ee0c7e3cdcb4d6170e899f70
Reviewed-by: Joerg Bornemann <joerg.bornemann@digia.com>
(cherry picked from qtbase/87054805872429c1c17135f9ae5364b050d3fdff)
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>