This change adds support for definitions and hover for builtin types and
functions. It also includes some small (non-logic) changes to the import
spec definition function.
Additionally, there are some resulting changes in diagnostics to ignore
the builtin file but also use it for definitions (Ian, you were right
with your comment on my earlier review...).
Fixesgolang/go#31696
Change-Id: I52d43d010a5ca8359b539c33e40782877eb730d0
Reviewed-on: https://go-review.googlesource.com/c/tools/+/177517
Run-TryBot: Rebecca Stambler <rstambler@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Cottrell <iancottrell@google.com>