tools/mkimage: backport gcc5 compatibility, patch

Fedora 22 includes gcc5 by default
build leads to error:
include/linux/compiler-gcc.h:114:30: fatal error: linux/compiler-gcc5.h: No such file or directory

backport upstream patch: "Add linux/compiler-gcc5.h to fix builds with gcc5"
id: 478b02f1a7043b673565075ea5016376f3293b23

Issue was reported at
https://forum.openwrt.org/viewtopic.php?id=56853
& replicated in a VM

created, flashed and tested ar71xx image successfully
as test

Signed-off-by: Dirk Neukirchen <dirkneukirchen@web.de>
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>

SVN-Revision: 45703

tools/mkimage/patches/200-gcc5_compat.patch

@@ -0,0 +1,93 @@
+From 478b02f1a7043b673565075ea5016376f3293b23 Mon Sep 17 00:00:00 2001
+From: Hans de Goede <hdegoede@redhat.com>
+Date: Sat, 7 Feb 2015 22:52:40 +0100
+Subject: [PATCH] Add linux/compiler-gcc5.h to fix builds with gcc5
+
+Add linux/compiler-gcc5/h from the kernel sources at:
+
+commit 5631b8fba640a4ab2f8a954f63a603fa34eda96b
+Author: Steven Noonan <steven@uplinklabs.net>
+Date:   Sat Oct 25 15:09:42 2014 -0700
+
+    compiler/gcc4+: Remove inaccurate comment about 'asm goto' miscompiles
+
+Signed-off-by: Hans de Goede <hdegoede@redhat.com>
+---
+ include/linux/compiler-gcc5.h |   65 +++++++++++++++++++++++++++++++++++++++++
+ 1 file changed, 65 insertions(+)
+ create mode 100644 include/linux/compiler-gcc5.h
+
+diff --git a/include/linux/compiler-gcc5.h b/include/linux/compiler-gcc5.h
+new file mode 100644
+index 0000000..c8c5659
+--- /dev/null
++++ b/include/linux/compiler-gcc5.h
+@@ -0,0 +1,65 @@
++#ifndef __LINUX_COMPILER_H
++#error "Please don't include <linux/compiler-gcc5.h> directly, include <linux/compiler.h> instead."
++#endif
++
++#define __used				__attribute__((__used__))
++#define __must_check			__attribute__((warn_unused_result))
++#define __compiler_offsetof(a, b)	__builtin_offsetof(a, b)
++
++/* Mark functions as cold. gcc will assume any path leading to a call
++   to them will be unlikely.  This means a lot of manual unlikely()s
++   are unnecessary now for any paths leading to the usual suspects
++   like BUG(), printk(), panic() etc. [but let's keep them for now for
++   older compilers]
++
++   Early snapshots of gcc 4.3 don't support this and we can't detect this
++   in the preprocessor, but we can live with this because they're unreleased.
++   Maketime probing would be overkill here.
++
++   gcc also has a __attribute__((__hot__)) to move hot functions into
++   a special section, but I don't see any sense in this right now in
++   the kernel context */
++#define __cold			__attribute__((__cold__))
++
++#define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__)
++
++#ifndef __CHECKER__
++# define __compiletime_warning(message) __attribute__((warning(message)))
++# define __compiletime_error(message) __attribute__((error(message)))
++#endif /* __CHECKER__ */
++
++/*
++ * Mark a position in code as unreachable.  This can be used to
++ * suppress control flow warnings after asm blocks that transfer
++ * control elsewhere.
++ *
++ * Early snapshots of gcc 4.5 don't support this and we can't detect
++ * this in the preprocessor, but we can live with this because they're
++ * unreleased.  Really, we need to have autoconf for the kernel.
++ */
++#define unreachable() __builtin_unreachable()
++
++/* Mark a function definition as prohibited from being cloned. */
++#define __noclone	__attribute__((__noclone__))
++
++/*
++ * Tell the optimizer that something else uses this function or variable.
++ */
++#define __visible __attribute__((externally_visible))
++
++/*
++ * GCC 'asm goto' miscompiles certain code sequences:
++ *
++ *   http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670
++ *
++ * Work it around via a compiler barrier quirk suggested by Jakub Jelinek.
++ *
++ * (asm goto is automatically volatile - the naming reflects this.)
++ */
++#define asm_volatile_goto(x...)	do { asm goto(x); asm (""); } while (0)
++
++#ifdef CONFIG_ARCH_USE_BUILTIN_BSWAP
++#define __HAVE_BUILTIN_BSWAP32__
++#define __HAVE_BUILTIN_BSWAP64__
++#define __HAVE_BUILTIN_BSWAP16__
++#endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP */
+-- 
+1.7.10.4
+