This change adds a quick fix for diagnostics that have an error message of the form "undeclared name: %s". It provides a quick fix to add a new variable with that name.
Updates golang/go#34644
Change-Id: I6534ee79d1770d1a62bac169c3c7e52e2443f39e
Reviewed-on: https://go-review.googlesource.com/c/tools/+/222237
Run-TryBot: Rohan Challa <rohan@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rebecca Stambler <rstambler@golang.org>
