This change adds severity levels to source.Diagnostics, allowing us to
pass this information along to the LSP. This allows compiler errors to
show up in red, while vet results show up in green.
Change-Id: I2bc0b27ed6629f987c05affe00fdbe4b9bfb3b3e
Reviewed-on: https://go-review.googlesource.com/c/164299
Run-TryBot: Rebecca Stambler <rstambler@golang.org>
Reviewed-by: Michael Matloob <matloob@golang.org>