racket: update to 6.4.

srcpkgs/racket/template

@@ -1,7 +1,7 @@
 # Template file for 'racket'
 pkgname=racket
-version=6.2
-revision=3
+version=6.4
+revision=1
 build_style=gnu-configure
 build_wrksrc=src
 hostmakedepends="gsfonts"
@@ -12,9 +12,10 @@ maintainer="Andrea Brancaleoni <miwaxe@gmail.com>"
 license="LGPL-3"
 homepage="http://racket-lang.org/"
 distfiles="http://mirror.racket-lang.org/installers/$version/$pkgname-$version-src.tgz"
-checksum=1331113742b3b3c26b5b95242c714379f1e5f325fad824bb28eeb7b4be03e615
+checksum=86afcebcd49cc734a3b1fdb525e78f5d57de6269f83de5c014f3cf9043c2dfe3
 nostrip=yes
 configure_args="--disable-docs"
+only_for_archs="i686 x86_64 armv5tel armv6l armv7l aarch64"
 
 if [ "$CROSS_BUILD" ]; then
 	configure_args+=" --enable-racket=/usr/bin/racket"

srcpkgs/racket/update

@@ -0,0 +1,2 @@
+site="https://api.github.com/repos/$pkgname/$pkgname/tags"
+pattern='"name":\s*"v\K[^\d]*([\d\.]+)(?=")'