Make sure that an embedded field like "MyStruct[T]" works and can be
referenced via the name MyStruct.
Change-Id: I8be1f1184dd42c4e54e4144aff2fd85e30af722f
Reviewed-on: https://go-review.googlesource.com/c/go/+/356312
Trust: Dan Scales <danscales@google.com>
Reviewed-by: Robert Griesemer <gri@golang.org>
