Preparation for generation of function literal type checking code
from types2 source.
Change-Id: I6b3029c34c2507d356ac8874154537bc6c38a715
Reviewed-on: https://go-review.googlesource.com/c/go/+/610995 Reviewed-by: Tim King <taking@google.com>
Auto-Submit: Robert Griesemer <gri@google.com> Reviewed-by: Robert Griesemer <gri@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>