[netstack] Make tcpip.Error savable.

Earlier we could not save tcpip.Error objects in structs because upon restore
the constant's address changes in netstack's error translation map and
translating the error would panic because the map is based on the address of the
tcpip.Error instead of the error itself.

Now I made that translations map use the error message as key instead of the
address. Added relevant synchronization mechanisms to protect the structure
and initialize it upon restore.

PiperOrigin-RevId: 346590485

0 files changed, 0 insertions, 0 deletions