package/mesa3d: fix build on riscv32

Fix the following build failure on riscv32:

../src/util/futex.h: In function 'sys_futex':
../src/util/futex.h:39:19: error: 'SYS_futex' undeclared (first use in this function); did you mean 'sys_futex'?
   39 |    return syscall(SYS_futex, addr1, op, val1, timeout, addr2, val3);
      |                   ^~~~~~~~~
      |                   sys_futex

Fixes:
 - http://autobuild.buildroot.org/results/692700a5f967760a0b8cd358b1712f1d5a7b681e

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
(cherry picked from commit 3298e67ac64ce1f52f58f1ef668c4c8c63309d04)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/mesa3d/0005-src-util-futex.h-fix-build-on-32-bit-architectures-u.patch

@@ -0,0 +1,43 @@
+From e501b7c17ada9c694d3f8302622b78d733485b38 Mon Sep 17 00:00:00 2001
+From: Fabrice Fontaine <fontaine.fabrice@gmail.com>
+Date: Sat, 21 Aug 2021 17:55:33 +0200
+Subject: [PATCH] src/util/futex.h: fix build on 32-bit architectures using
+ 64-bit time_t
+
+Fix the following build failure on 32-bit architectures using 64-bit
+time_t (e.g. riscv32):
+
+../src/util/futex.h: In function 'sys_futex':
+../src/util/futex.h:39:19: error: 'SYS_futex' undeclared (first use in this function); did you mean 'sys_futex'?
+   39 |    return syscall(SYS_futex, addr1, op, val1, timeout, addr2, val3);
+      |                   ^~~~~~~~~
+      |                   sys_futex
+
+Fixes:
+ - http://autobuild.buildroot.org/results/692700a5f967760a0b8cd358b1712f1d5a7b681e
+
+Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
+[Upstream status:
+https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/12496]
+---
+ src/util/futex.h | 4 ++++
+ 1 file changed, 4 insertions(+)
+
+diff --git a/src/util/futex.h b/src/util/futex.h
+index 43097f4cd5b..221eda9db0c 100644
+--- a/src/util/futex.h
++++ b/src/util/futex.h
+@@ -34,6 +34,10 @@
+ #include <sys/syscall.h>
+ #include <sys/time.h>
+ 
++#ifndef SYS_futex
++#define SYS_futex SYS_futex_time64
++#endif
++
+ static inline long sys_futex(void *addr1, int op, int val1, const struct timespec *timeout, void *addr2, int val3)
+ {
+    return syscall(SYS_futex, addr1, op, val1, timeout, addr2, val3);
+-- 
+2.32.0
+