WIP hashbrown support

Author: Amanieu

src/Cargo.lock

@@ -896,6 +896,15 @@ dependencies = [
  "serde_json 1.0.31 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "hashbrown"
+version = "0.1.2"
+source = "git+https://github.com/Amanieu/hashbrown.git?branch=stage0#50ddb15f515c1eaa31125a229b68fdf5f2cc2ce2"
+dependencies = [
+ "byteorder 1.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "scopeguard 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "hex"
 version = "0.3.2"
@@ -2162,6 +2171,7 @@ dependencies = [
  "cfg-if 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "ena 0.9.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "graphviz 0.0.0",
+ "hashbrown 0.1.2 (git+https://github.com/Amanieu/hashbrown.git?branch=stage0)",
  "log 0.4.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.6.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot_core 0.2.14 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -3249,6 +3259,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum glob 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)" = "8be18de09a56b60ed0edf84bc9df007e30040691af7acd1c41874faac5895bfb"
 "checksum globset 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)" = "8e49edbcc9c7fc5beb8c0a54e7319ff8bed353a2b55e85811c6281188c2a6c84"
 "checksum handlebars 0.32.4 (registry+https://github.com/rust-lang/crates.io-index)" = "d89ec99d1594f285d4590fc32bac5f75cdab383f1123d504d27862c644a807dd"
+"checksum hashbrown 0.1.2 (git+https://github.com/Amanieu/hashbrown.git?branch=stage0)" = "<none>"
 "checksum hex 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)" = "805026a5d0141ffc30abb3be3173848ad46a1b1664fe632428479619a3644d77"
 "checksum home 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "80dff82fb58cfbbc617fb9a9184b010be0529201553cda50ad04372bc2333aff"
 "checksum html5ever 0.22.3 (registry+https://github.com/rust-lang/crates.io-index)" = "b04478cf718862650a0bf66acaf8f2f8c906fbc703f35c916c1f4211b069a364"

src/librustc_data_structures/Cargo.toml

@@ -21,6 +21,7 @@ rustc-rayon = "0.1.1"
 rustc-rayon-core = "0.1.1"
 rustc-hash = "1.0.1"
 smallvec = { version = "0.6.5", features = ["union"] }
+hashbrown = { git = "https://github.com/Amanieu/hashbrown.git", branch = "stage0" }
 
 [dependencies.parking_lot]
 version = "0.6"

src/librustc_data_structures/fx.rs

@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-pub use rustc_hash::FxHashMap;
-pub use rustc_hash::FxHashSet;
+use core::hash::BuildHasherDefault;
+pub type FxHashMap<K, V> = hashbrown::HashMap<K, V, BuildHasherDefault<FxHasher>>;
+pub type FxHashSet<K> = hashbrown::HashSet<K, BuildHasherDefault<FxHasher>>;
 pub use rustc_hash::FxHasher;
+pub use hashbrown::hash_map::Entry;

src/librustc_data_structures/lib.rs

@@ -51,6 +51,7 @@ extern crate rustc_hash;
 extern crate serialize;
 extern crate graphviz;
 extern crate smallvec;
+extern crate hashbrown;
 
 // See librustc_cratesio_shim/Cargo.toml for a comment explaining this.
 #[allow(unused_extern_crates)]

src/librustc_data_structures/obligation_forest/mod.rs

@@ -18,7 +18,7 @@
 use fx::{FxHashMap, FxHashSet};
 
 use std::cell::Cell;
-use std::collections::hash_map::Entry;
+use fx::Entry;
 use std::fmt::Debug;
 use std::hash;
 use std::marker::PhantomData;

src/libsyntax/ext/tt/macro_parser.rs

@@ -97,7 +97,7 @@ use symbol::keywords;
 use tokenstream::{DelimSpan, TokenStream};
 
 use rustc_data_structures::fx::FxHashMap;
-use std::collections::hash_map::Entry::{Occupied, Vacant};
+use rustc_data_structures::fx::Entry::{Occupied, Vacant};
 use std::mem;
 use std::ops::{Deref, DerefMut};
 use std::rc::Rc;

src/libsyntax/ext/tt/macro_rules.rs

@@ -29,7 +29,7 @@ use tokenstream::{DelimSpan, TokenStream, TokenTree};
 
 use rustc_data_structures::fx::FxHashMap;
 use std::borrow::Cow;
-use std::collections::hash_map::Entry;
+use rustc_data_structures::fx::Entry;
 
 use rustc_data_structures::sync::Lrc;
 use errors::Applicability;

src/libsyntax_ext/format.rs

@@ -26,7 +26,7 @@ use errors::Applicability;
 
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use std::borrow::Cow;
-use std::collections::hash_map::Entry;
+use rustc_data_structures::fx::Entry;
 
 #[derive(PartialEq)]
 enum ArgumentType {