[dev.typeparams] go/types: implement <-ch where ch is of type parameter type
This is a port of CL 333709 to go/types, adjusted for the different
error API.
Fixes #43671
Change-Id: Ifd340149bfbcabe401cec74398cb83f2ae812e51
Reviewed-on: https://go-review.googlesource.com/c/go/+/335075
Trust: Robert Findley <rfindley@google.com>
Run-TryBot: Robert Findley <rfindley@google.com>
TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Robert Griesemer <gri@golang.org>