Add additional bug reporting related to position invariants, and update
marker test runners to panic on encountered bugs.
This revealed a panic on older Go versions, where we try to create a
range for a missing package name span. Lift the check into the caller
for this case, and leave a big comment explaining that
checkForOrphanedFile probably shouldn't be so tolerant of invalid calls.
Change-Id: Ie16a07afba0f8a5682cca50ad8f04450bfa2da65
Reviewed-on: https://go-review.googlesource.com/c/tools/+/407885
Reviewed-by: Alan Donovan <adonovan@google.com>
Run-TryBot: Robert Findley <rfindley@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
gopls-CI: kokoro <noreply+kokoro@google.com>
2bb78cf04e