cmd/compile/internal/typecheck: avoid use of Name.Ntype for assignments
Prep refactoring for the next CL, which removes Name.Ntype
entirely. Pulled out separately because this logic is a little subtle,
so this should be easier to bisect in case there's something I'm
missing here.
Change-Id: I4ffec6ee62fcd036582e8d2c963edcbd8bac184f
Reviewed-on: https://go-review.googlesource.com/c/go/+/403837 Reviewed-by: David Chase <drchase@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>