Rollup merge of #58220 - taiki-e:libprofiler_builtins-2018, r=Centril

libprofiler_builtins => 2018

Transitions `libprofiler_builtins` to Rust 2018; cc #58099

r? @Centril

src/libprofiler_builtins/Cargo.toml

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

src/libprofiler_builtins/build.rs

@@ -2,8 +2,6 @@
 //!
 //! See the build.rs for libcompiler_builtins crate for details.
 
-extern crate cc;
-
 use std::env;
 use std::path::Path;
 

src/libprofiler_builtins/lib.rs

@@ -5,5 +5,5 @@
             reason = "internal implementation detail of rustc right now",
             issue = "0")]
 #![allow(unused_features)]
-#![feature(nll)]
 #![feature(staged_api)]
+#![deny(rust_2018_idioms)]