* except.c: Support for catching a list of types with a single handler
        (struct eh_region): Change type and filter to lists for catch regions.
        (mark_eh_region): Mark the filter list for GC also.
        (expand_start_catch): Always build a list if argument not NULL and
        register each type of the list through add_type_for_runtime.
        (duplicate_eh_region_1): Change type into type_list for catch regions.
        (assign_filter_values): Assign a filter to each type associated with a
        catch region. Assign filter for NULL types in a unique entry in the
        filter list.
        (build_post_landing_pads): Emit compare and jump for each filter of
        the list associated with a catch region.
        (reachable_next_level): When the type thrown is known, stop the search
        as soon as one type within a catch list matches. Also, a handler is
        potentially reachable only if at least one of the types it catches
        has not been previously caught.
        (collect_one_action_chain): Retrieve the filter for a NULL type list
        from the first filter list entry. For non NULL type lists, add an
        action record for every filter assigned.
        * except.h: Reflect changes in comment before expand_start_catch.

From-SVN: r47087