I'm not sure how this can happen, but it seems possible that a bad
expression might somehow have an invalid position.
Fixesgolang/go#47231
Change-Id: I0794bdfb66f668fc375e9fe561c9f239c8b92492
Reviewed-on: https://go-review.googlesource.com/c/tools/+/334892
Trust: Rebecca Stambler <rstambler@golang.org>
Run-TryBot: Rebecca Stambler <rstambler@golang.org>
gopls-CI: kokoro <noreply+kokoro@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>