rust: use upstream patches to fix build with 1.17

No rebuild required.

srcpkgs/rust/patches/4caa0b020f146e4504ab8ffdd52df29deaa49a09.patch

@@ -0,0 +1,65 @@
+From 4caa0b020f146e4504ab8ffdd52df29deaa49a09 Mon Sep 17 00:00:00 2001
+From: Mark Simulacrum <mark.simulacrum@gmail.com>
+Date: Tue, 20 Jun 2017 18:04:36 -0600
+Subject: [PATCH] Fixes bootstrapping with custom cargo/rustc.
+
+config.mk is now always read when parsing the configuration to prevent
+this from reoccurring in the future, hopefully.
+---
+ src/bootstrap/bin/main.rs |  8 +-------
+ src/bootstrap/config.rs   | 10 ++++++++--
+ 2 files changed, 9 insertions(+), 9 deletions(-)
+
+diff --git a/src/bootstrap/bin/main.rs b/src/bootstrap/bin/main.rs
+index 5ca5ce1648f2..5ef18b89841f 100644
+--- a/src/bootstrap/bin/main.rs
++++ b/src/bootstrap/bin/main.rs
+@@ -26,12 +26,6 @@ use bootstrap::{Flags, Config, Build};
+ fn main() {
+     let args = env::args().skip(1).collect::<Vec<_>>();
+     let flags = Flags::parse(&args);
+-    let mut config = Config::parse(&flags.build, flags.config.clone());
+-
+-    // compat with `./configure` while we're still using that
+-    if std::fs::metadata("config.mk").is_ok() {
+-        config.update_with_config_mk();
+-    }
+-
++    let config = Config::parse(&flags.build, flags.config.clone());
+     Build::new(flags, config).build();
+ }
+diff --git a/src/bootstrap/config.rs b/src/bootstrap/config.rs
+index fd8aa320fb3d..902cd0997a8e 100644
+--- a/src/bootstrap/config.rs
++++ b/src/bootstrap/config.rs
+@@ -15,7 +15,7 @@
+ 
+ use std::collections::HashMap;
+ use std::env;
+-use std::fs::File;
++use std::fs::{self, File};
+ use std::io::prelude::*;
+ use std::path::PathBuf;
+ use std::process;
+@@ -410,6 +410,12 @@ impl Config {
+             set(&mut config.rust_dist_src, t.src_tarball);
+         }
+ 
++
++        // compat with `./configure` while we're still using that
++        if fs::metadata("config.mk").is_ok() {
++            config.update_with_config_mk();
++        }
++
+         return config
+     }
+ 
+@@ -418,7 +424,7 @@ impl Config {
+     /// While we still have `./configure` this implements the ability to decode
+     /// that configuration into this. This isn't exactly a full-blown makefile
+     /// parser, but hey it gets the job done!
+-    pub fn update_with_config_mk(&mut self) {
++    fn update_with_config_mk(&mut self) {
+         let mut config = String::new();
+         File::open("config.mk").unwrap().read_to_string(&mut config).unwrap();
+         for line in config.lines() {

srcpkgs/rust/patches/73267374d4176ac1c5d685ff2bac36556cfa4730.patch

@@ -0,0 +1,48 @@
+From 73267374d4176ac1c5d685ff2bac36556cfa4730 Mon Sep 17 00:00:00 2001
+From: Mark Simulacrum <mark.simulacrum@gmail.com>
+Date: Fri, 16 Jun 2017 07:44:09 -0600
+Subject: [PATCH] Use custom cargo/rustc paths when parsing flags.
+
+---
+ src/bootstrap/flags.rs | 17 ++++++++---------
+ 1 file changed, 8 insertions(+), 9 deletions(-)
+
+diff --git a/src/bootstrap/flags.rs b/src/bootstrap/flags.rs
+index 56cbb4cecf2a..dc9dac736278 100644
+--- a/src/bootstrap/flags.rs
++++ b/src/bootstrap/flags.rs
+@@ -242,11 +242,18 @@ Arguments:
+         let cwd = t!(env::current_dir());
+         let paths = matches.free[1..].iter().map(|p| cwd.join(p)).collect::<Vec<_>>();
+ 
++        let cfg_file = matches.opt_str("config").map(PathBuf::from).or_else(|| {
++            if fs::metadata("config.toml").is_ok() {
++                Some(PathBuf::from("config.toml"))
++            } else {
++                None
++            }
++        });
+ 
+         // All subcommands can have an optional "Available paths" section
+         if matches.opt_present("verbose") {
+             let flags = Flags::parse(&["build".to_string()]);
+-            let mut config = Config::default();
++            let mut config = Config::parse(&flags.build, cfg_file.clone());
+             config.build = flags.build.clone();
+             let mut build = Build::new(flags, config);
+             metadata::build(&mut build);
+@@ -307,14 +314,6 @@ Arguments:
+         };
+ 
+ 
+-        let cfg_file = matches.opt_str("config").map(PathBuf::from).or_else(|| {
+-            if fs::metadata("config.toml").is_ok() {
+-                Some(PathBuf::from("config.toml"))
+-            } else {
+-                None
+-            }
+-        });
+-
+         let mut stage = matches.opt_str("stage").map(|j| j.parse().unwrap());
+ 
+         if matches.opt_present("incremental") {

srcpkgs/rust/patches/cargo-hack.patch

@@ -1,11 +0,0 @@
---- rustc-1.18.0-src/src/bootstrap/lib.rs.orig
-+++ rustc-1.18.0-src/src/bootstrap/lib.rs
-@@ -220,7 +220,7 @@
-         };
-         let cargo = match config.cargo {
-             Some(ref s) => PathBuf::from(s),
--            None => stage0_root.join(exe("cargo", &config.build)),
-+            None => PathBuf::from("cargo")
-         };
-         let local_rebuild = config.local_rebuild;
-