go/types: suppress index-out-of-bounds error on Unknown constants
Follow up to CL 312591, which was stumping rfindley and I for a
while. Credit to him for figuring out a repro and explaining the
correct solution.
Change-Id: Ib8578bba05f60fc41d382c34c5266d815441e7a1
Reviewed-on: https://go-review.googlesource.com/c/go/+/312790
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Trust: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Robert Findley <rfindley@google.com>