flow.c (make_edge): Accept an optional 2D bitmap in which to cache edge existence.

flow.c (make_edge): Accept an optional 2D bitmap in which to cache edge existence.

        * flow.c (make_edge): Accept an optional 2D bitmap in which
        to cache edge existence.  Update all callers.
        (make_label_edge, make_eh_edge): Pass through the edge cache.
        (make_edges): Provide the cache.

From-SVN: r29828