cmd/compile/internal/types2: record all instances, not just inferred instances
This is a port of CL 349629 from go/types to types2, adjusted to
make it work for types2. It also includes the necessary compiler
changes, provided by mdempsky.
Change-Id: If8de174cee9c69df0d0642fcec1ee7622b7c3852
Reviewed-on: https://go-review.googlesource.com/c/go/+/351455
Trust: Robert Griesemer <gri@golang.org>
Trust: Dan Scales <danscales@google.com>
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Robert Findley <rfindley@google.com> Reviewed-by: Dan Scales <danscales@google.com>