top-level use statements are sometimes deleted when rearraged.

[dr-bonez]

Tested in VSCode with latest rls and Format on Save:

use crate::stuff;
use failure::Error;
use r2d2::ConnectionManager;
use diesel::PgConnection;

becomes

use crate::stuff;
use diesel::PgConnection;
use r2d2::ConnectionManager;

This deleted an import.
I have observed this behavior consistently on any set of mis-ordered imports.

[topecongiro]

Couldn't reproduce this locally. This is probably due to a bug in VSCode extension. cc rust-lang/vscode-rust#595.