gnu: rust: Update rust to 1.22.1 and cargo to 1.23.0.

* gnu/packages/rust.scm (%rust-bootstrap-binaries-version): Update version.
(%rust-bootstrap-binaries): Use x86_64 rust bootstrap package for x86_64 build.
(%cargo-reference-project-file): Use specific file as "project" file when
patching rust vendored sources.
(%cargo-reference-hash): sha256 sum for %cargo-reference-project-file.
(rustc-bootstrap): Use bootstrap package with host architecture.
(cargo-bootstrap): Use bootstrap package with host architecture.
(rustc): Add new test dependency, fix build issues, use "./x.py" script for
build instead of "./configure".
(cargo): Update dependencies, patch shebangs for vendored sources
* gnu/packages/jemalloc.scm: Add jemalloc-4.5.0 release.

Signed-off-by: Danny Milosavljevic <dannym@scratchpost.org>

gnu/packages/jemalloc.scm

@@ -23,6 +23,7 @@
   #:use-module ((guix licenses) #:select (bsd-2))
   #:use-module (guix packages)
   #:use-module (guix download)
+  #:use-module (guix utils)
   #:use-module (gnu packages perl)
   #:use-module (guix build-system gnu))
 
@@ -62,3 +63,17 @@
      "This library providing a malloc(3) implementation that emphasizes
 fragmentation avoidance and scalable concurrency support.")
     (license bsd-2)))
+
+(define-public jemalloc-4.5.0
+  (package
+    (inherit jemalloc)
+    (version "4.5.0")
+    (source (origin
+              (method url-fetch)
+              (uri (string-append
+                    "https://github.com/jemalloc/jemalloc/releases/download/"
+                    version "/jemalloc-" version ".tar.bz2"))
+              (sha256
+               (base32
+                "10373xhpc10pgmai9fkc1z0rs029qlcb3c0qfnvkbwdlcibdh2cl"))))
+    (inputs '())))