move to 2018 edition

I want NLL :D

Author: RalfJung

Cargo.toml

@@ -9,6 +9,7 @@ repository = "https://github.com/solson/miri"
 version = "0.1.0"
 build = "build.rs"
 default-run = "miri"
+edition = "2018"
 
 [lib]
 test = true # we have unit tests

src/bin/miri-rustc-tests.rs

@@ -1,4 +1,4 @@
-#![feature(rustc_private)]
+#![feature(rustc_private, extern_crate_item_prelude)]
 extern crate miri;
 extern crate getopts;
 extern crate rustc;

src/bin/miri.rs

@@ -1,4 +1,4 @@
-#![feature(rustc_private)]
+#![feature(rustc_private, extern_crate_item_prelude)]
 
 extern crate getopts;
 extern crate miri;

src/lib.rs

@@ -1,4 +1,4 @@
-#![feature(rustc_private)]
+#![feature(rustc_private, extern_crate_item_prelude)]
 
 #![cfg_attr(feature = "cargo-clippy", allow(cast_lossless))]
 
@@ -253,7 +253,7 @@ impl Into<MemoryKind<MiriMemoryKind>> for MiriMemoryKind {
 impl MayLeak for MiriMemoryKind {
     #[inline(always)]
     fn may_leak(self) -> bool {
-        use MiriMemoryKind::*;
+        use self::MiriMemoryKind::*;
         match self {
             Rust | C => false,
             Env | MutStatic => true,