Basic compiler infra

compiler/rustc_builtin_macros/src/lib.rs

@@ -1,17 +1,18 @@
 //! This crate contains implementations of built-in macros and other code generating facilities
 //! injecting code into the crate before it is lowered to HIR.
 
+#![allow(rustc::potential_query_instability)]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![feature(array_windows)]
 #![feature(box_patterns)]
 #![feature(decl_macro)]
 #![feature(is_sorted)]
-#![feature(nll)]
+#![feature(let_chains)]
 #![feature(let_else)]
+#![feature(nll)]
 #![feature(proc_macro_internals)]
 #![feature(proc_macro_quote)]
 #![recursion_limit = "256"]
-#![allow(rustc::potential_query_instability)]
 
 extern crate proc_macro;