1. Fixed "use of deprecated item 'rustc_plugin': import this through …

…`rustc_driver::plugin` instead to make TLS work correctly. See rust-lang/rust#62717"

2. Updated to `rust nightly e44fdf979 2019-08-21`

src/lib.rs

@@ -198,6 +198,7 @@ Licensed under the Apache License, Version 2.0
 extern crate syntax;
 extern crate rustc_driver;
 
+
 mod nightly;
 pub use self::nightly::*;