libGL: unbreak x86_64/musl.

srcpkgs/libGL/patches/configure.ac.patch

@@ -0,0 +1,26 @@
+- remove libpthread stubs
+- detect static_assert() correctly for musl
+
+--- configure.ac.orig	2016-11-01 14:39:59.000000000 +0100
++++ configure.ac	2016-11-04 13:07:05.317813259 +0100
+@@ -828,7 +828,7 @@
+ 
+ dnl pthread-stubs is mandatory on targets where it exists
+ case "$host_os" in
+-cygwin* )
++cygwin* | linux* )
+     pthread_stubs_possible="no"
+     ;;
+ * )
+@@ -1919,6 +1919,11 @@
+ fi
+ AM_CONDITIONAL(HAVE_ST_NINE, test "x$enable_nine" = xyes)
+ 
++AC_CHECK_DECL(static_assert, [],
++	[AC_DEFINE(static_assert(...), [/* */], [noop static_assert() replacement]),
++	AC_MSG_RESULT([no])],
++	[[#include <assert.h>]])
++
+ dnl
+ dnl OpenCL configuration
+ dnl

srcpkgs/libGL/patches/musl-endian.patch

@@ -0,0 +1,11 @@
+--- src/util/u_endian.h.orig	2016-11-04 12:16:00.480356454 +0100
++++ src/util/u_endian.h	2016-11-04 12:16:11.984347944 +0100
+@@ -27,7 +27,7 @@
+ #ifndef U_ENDIAN_H
+ #define U_ENDIAN_H
+ 
+-#if defined(__GLIBC__) || defined(ANDROID)
++#if defined(__linux__) || defined(ANDROID)
+ #include <endian.h>
+ 
+ #if __BYTE_ORDER == __LITTLE_ENDIAN

srcpkgs/libGL/patches/remove-libpthread-stubs.patch

@@ -1,13 +0,0 @@
-diff --git configure.ac configure.ac
-index 54416b4..8a708d3 100644
---- configure.ac
-+++ configure.ac
-@@ -824,7 +824,7 @@ test -z "$PTHREAD_LIBS" && PTHREAD_LIBS="-lpthread"
- 
- dnl pthread-stubs is mandatory on targets where it exists
- case "$host_os" in
--cygwin* )
-+cygwin* | linux* )
-     pthread_stubs_possible="no"
-     ;;
- * )

srcpkgs/libGL/template

@@ -1,7 +1,7 @@
 # Template build file for 'libGL'.
 pkgname=libGL
 version=13.0.0
-revision=1
+revision=2
 wrksrc="mesa-${version}"
 build_style=gnu-configure
 configure_args="--enable-shared-glapi --enable-gbm
@@ -15,6 +15,9 @@ license="MIT, LGPL-2.1"
 distfiles="https://mesa.freedesktop.org/archive/${version}/mesa-${version}.tar.xz"
 checksum=94edb4ebff82066a68be79d9c2627f15995e1fe10f67ab3fc63deb842027d727
 
+# static_assert()
+CFLAGS="-std=c11"
+
 hostmakedepends="
  automake libtool flex pkg-config llvm python-Mako libxml2-python wayland-devel"
 makedepends="