Rollup merge of #58219 - taiki-e:librustc_asan-2018, r=Centril

librustc_asan => 2018

Transitions `librustc_asan` to Rust 2018; cc #58099

r? @Centril

src/librustc_asan/Cargo.toml

@@ -3,6 +3,7 @@ authors = ["The Rust Project Developers"]
 build = "build.rs"
 name = "rustc_asan"
 version = "0.0.0"
+edition = "2018"
 
 [lib]
 name = "rustc_asan"

src/librustc_asan/build.rs

@@ -1,6 +1,3 @@
-extern crate build_helper;
-extern crate cmake;
-
 use std::env;
 use build_helper::sanitizer_lib_boilerplate;
 

src/librustc_asan/lib.rs

@@ -1,8 +1,9 @@
 #![sanitizer_runtime]
-#![feature(nll)]
 #![feature(sanitizer_runtime)]
 #![feature(staged_api)]
 #![no_std]
 #![unstable(feature = "sanitizer_runtime_lib",
             reason = "internal implementation detail of sanitizers",
             issue = "0")]
+
+#![deny(rust_2018_idioms)]