types2, go/types: fix type checking of ~[]E passing to unsafe builtins

types2, go/types: fix type checking of ~[]E passing to unsafe builtins

Fixes #64406

Change-Id: I58002ad722a229fe6db0be08d745fbad86048c6d
Reviewed-on: https://go-review.googlesource.com/c/go/+/545395
Reviewed-by: Robert Griesemer <gri@google.com>
Run-TryBot: Robert Griesemer <gri@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Bryan Mills <bcmills@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Auto-Submit: Robert Griesemer <gri@google.com>