package/x11r7/xserver_xorg-server: fix building on mips with GCC10

Port the following upstream commit:
https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/591/diffs?commit_id=0148a15da1616a868d71abe1b56e3f28cc79533c

This fixes the following build error on mips with GCC10:
  CCLD     libint10.la
buildroot/output/host/lib/gcc/mips64el-buildroot-linux-gnu/10.3.0/../../../../mips64el-buildroot-linux-gnu/bin/ld: .libs/helper_mem.o:(.bss+0x0): multiple definition of `IOPortBase'; .libs/helper_exec.o:(.bss+0x0): first defined here

Signed-off-by: Raphaël Mélotte <raphael.melotte@mind.be>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
(cherry picked from commit 2e52de40d2e028707e5c20d55805fe616c106b15)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/x11r7/xserver_xorg-server/0006-compiler.h-don-t-define-inb-outb-and-friends-on-mips.patch

@@ -0,0 +1,73 @@
+From de5e24b5036a1a5a877f8f30169e3497d0e296d6 Mon Sep 17 00:00:00 2001
+From: Julien Cristau <jcristau@debian.org>
+Date: Wed, 6 Jan 2021 10:20:53 +0100
+Subject: [PATCH] compiler.h: don't define inb/outb and friends on mips
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+The definition relies on IOPortBase, which is only ever set in
+hw/xfree86/os-support/bsd/arm_video.c
+
+This caused build failures on linux/mips with GCC 10, due to this
+change (from https://gcc.gnu.org/gcc-10/changes.html#c):
+
+"GCC now defaults to -fno-common. As a result, global variable accesses
+are more efficient on various targets. In C, global variables with
+multiple tentative definitions now result in linker errors. With
+-fcommon such definitions are silently merged during linking."
+
+As a result anything including compiler.h would get its own definition
+of IOPortBase and the linker would error out.
+
+Signed-off-by: Raphaël Mélotte <raphael.melotte@mind.be>
+---
+ hw/xfree86/common/compiler.h          | 8 ++------
+ hw/xfree86/os-support/bsd/arm_video.c | 3 +++
+ 2 files changed, 5 insertions(+), 6 deletions(-)
+
+diff --git a/hw/xfree86/common/compiler.h b/hw/xfree86/common/compiler.h
+index 2b2008b3f..eb788d3fd 100644
+--- a/hw/xfree86/common/compiler.h
++++ b/hw/xfree86/common/compiler.h
+@@ -518,14 +518,10 @@ xf86WriteMmio32Le(__volatile__ void *base, const unsigned long offset,
+     barrier();
+ }
+ 
+-#elif defined(__mips__) || (defined(__arm32__) && !defined(__linux__))
+-#if defined(__arm32__) || defined(__mips64)
++#elif defined(__arm32__) && !defined(__linux__)
+ #define PORT_SIZE long
+-#else
+-#define PORT_SIZE short
+-#endif
+ 
+-_X_EXPORT unsigned int IOPortBase;      /* Memory mapped I/O port area */
++extern _X_EXPORT unsigned int IOPortBase;      /* Memory mapped I/O port area */
+ 
+ static __inline__ void
+ outb(unsigned PORT_SIZE port, unsigned char val)
+diff --git a/hw/xfree86/os-support/bsd/arm_video.c b/hw/xfree86/os-support/bsd/arm_video.c
+index dd1020e33..180d70543 100644
+--- a/hw/xfree86/os-support/bsd/arm_video.c
++++ b/hw/xfree86/os-support/bsd/arm_video.c
+@@ -65,6 +65,7 @@
+ #include "xf86Priv.h"
+ #include "xf86_OSlib.h"
+ #include "xf86OSpriv.h"
++#include "compiler.h"
+ 
+ #if defined(__NetBSD__) && !defined(MAP_FILE)
+ #define MAP_FLAGS MAP_SHARED
+@@ -162,6 +163,8 @@ xf86DisableIO()
+ 
+ #if defined(USE_ARC_MMAP) || defined(__arm32__)
+ 
++unsigned int IOPortBase;
++
+ Bool
+ xf86EnableIO()
+ {
+-- 
+2.32.0
+