guix: mescc-tools: Update to 0.7.0, adding ARM support.

This brings arm-linux-gnueabihf, aarch64-linux-gnu support.

* guix/git/mes.scm (mescc-tools): Update to 0.7.0.

guix/git/mes.scm

@@ -46,15 +46,17 @@
   #:use-module (guix download)
   #:use-module (guix git-download)
   #:use-module (guix licenses)
-  #:use-module (guix packages))
+  #:use-module (guix packages)
+  #:use-module (guix utils))
 
 (define %source-dir (getcwd))
 
 (define-public mescc-tools
   (package
     (name "mescc-tools")
-    (version "0.6.1")
-    (source (origin
+    (version "0.7.0")
+    (source
+     (origin
        (method url-fetch)
        (uri (string-append
              "http://git.savannah.nongnu.org/cgit/mescc-tools.git/snapshot/"
@@ -63,15 +65,21 @@
        (file-name (string-append name "-" version ".tar.gz"))
        (sha256
         (base32
-                "06jpvq6xfjzn2al6b4rdwd3zv3h4cvilc4n9gqcnjr9cr6wjpw2n"))))
+         "1p1ijia4rm3002f5sypidl9v5gq0mlch9b0n61rpxkdsaaxjqax3"))))
     (build-system gnu-build-system)
-    (supported-systems '("i686-linux" "x86_64-linux"))
+    (supported-systems
+     '("aarch64-linux" "armhf-linux" "i686-linux" "x86_64-linux"))
     (arguments
      `(#:make-flags (list (string-append "PREFIX=" (assoc-ref %outputs "out"))
-                          "CC=gcc")
+                          (string-append "CC=" ,(cc-for-target)))
        #:test-target "test"
        #:phases (modify-phases %standard-phases
-                  (delete 'configure))))
+                  (delete 'configure)
+                  (add-after 'unpack 'patch-prefix
+                    (lambda _
+                      (substitute* "sha256.sh"
+                        (("/usr/bin/sha256sum") (which "sha256sum")))
+                      #t)))))
     (synopsis "Tools for the full source bootstrapping process")
     (description
      "Mescc-tools is a collection of tools for use in a full source