go/types, types2: disentangle convoluted logic for missing method cause
Use a state to exactly track lookup results. In case of lookup failure,
use the state to directly report the cause instead of trying to guess
from the missing and alternative method.
Addresses a TODO (incorrect error message).
Change-Id: I50902752deab741f8199a09fd1ed29286cf5be42
Reviewed-on: https://go-review.googlesource.com/c/go/+/472637
TryBot-Result: Gopher Robot <gobot@golang.org>
Auto-Submit: Robert Griesemer <gri@google.com> Reviewed-by: Robert Findley <rfindley@google.com>
Run-TryBot: Robert Griesemer <gri@google.com> Reviewed-by: Robert Griesemer <gri@google.com>