libxml2: add a patch to fix segfaults with yelp and others, from Arch.

srcpkgs/libxml2/patches/largefile64.patch

@@ -0,0 +1,12 @@
+--- libxml.h.orig
++++ libxml.h
+@@ -13,6 +13,9 @@
+ #ifndef _LARGEFILE_SOURCE
+ #define _LARGEFILE_SOURCE
+ #endif
++#ifndef _LARGEFILE64_SOURCE
++#define _LARGEFILE64_SOURCE
++#endif
+ #ifndef _FILE_OFFSET_BITS
+ #define _FILE_OFFSET_BITS 64
+ #endif

srcpkgs/libxml2/template

@@ -1,6 +1,7 @@
 # Template build file for 'libxml2'.
 pkgname=libxml2
 version=2.7.7
+revision=1
 distfiles="http://xmlsoft.org/sources/$pkgname-$version.tar.gz"
 build_style=gnu_configure
 short_desc="Library providing XML and HTML support"