The spec was adjusted in commit df410d6a4842 to allow the
implicit assignment of strutures with unexported fields in
method receivers.  This change updates the compiler.

Also moved bug322 into fixedbugs and updated golden.out
to reflect the removal of the last known bug.

Fixes #1402.

R=golang-dev, gri, rsc
CC=golang-dev
https://golang.org/cl/4526069