The file gnu_java_net_PlainDatagramSocketImpl.c has a bug where it
sets the port in the received datagram byte-swapped. This is because
it thinks it needs to byte-swap it, which is incorrect, because it's
already been byte-swapped earlier by the
TARGET_NATIVE_NETWORK_SOCKET_RECEIVE_WITH_ADDRESS_PORT() macro
(which is invoked from _javanet_recvfrom()).
This patch fixes it... I'll commit if there are no complaints.
I'm a little suspiciou though whether I'm the only one seeing this.
For me this bug always causes the Mauve test suite to hang indefinitely
during the "gnu.testlet.java.net.DatagramSocket.DatagramSocketTest" test,
so I'd think other people would have noticed it before.