Remove unused sysroot rust crates

Author: Xanewok

rls/src/build/rustc.rs

@@ -1,24 +1,14 @@
 // FIXME: switch to something more ergonomic here, once available.
 // (Currently, there is no way to opt into sysroot crates without `extern crate`.)
 #[allow(unused_extern_crates)]
-extern crate getopts;
-#[allow(unused_extern_crates)]
-extern crate rustc_session;
-#[allow(unused_extern_crates)]
-extern crate rustc_codegen_utils;
-#[allow(unused_extern_crates)]
 extern crate rustc_driver;
 #[allow(unused_extern_crates)]
-extern crate rustc_errors;
-#[allow(unused_extern_crates)]
 extern crate rustc_interface;
 #[allow(unused_extern_crates)]
-extern crate rustc_metadata;
-#[allow(unused_extern_crates)]
-extern crate rustc_resolve;
-#[allow(unused_extern_crates)]
 extern crate rustc_save_analysis;
 #[allow(unused_extern_crates)]
+extern crate rustc_session;
+#[allow(unused_extern_crates)]
 extern crate rustc_span;
 
 use std::collections::{BTreeMap, HashMap, HashSet};