cmd/compile/internal/noder: shuffle defined type handling code
Per TODO, this CL just moves code around without behavioral
change. Part of a cleanup process so that it's easier to access object
dictionaries where needed.
Change-Id: I95bb3cdd3cdb46cae47d76d5c1d5d8256661f222
Reviewed-on: https://go-review.googlesource.com/c/go/+/421816
TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Than McIntosh <thanm@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com> Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>