While the patch makes it compile, the result will not
work as expected because the semantics of the "flags"
are different in Linux and NetBSD.
In Linux there is a "MAYMOVE" bit which explicitely
allows the start address to change. In NetBSD, this
is default behaviour. So there is even the danger that
NetBSD changes the address for an application which
does not allow that (and does not check).

best regards
Matthias