buildgcc: Add patch to work around Musl libc issue

GCC includes `sched.h` after poisoning calloc(). This results in a
build failure with Musl libc. We work around the issue by including
`sched.h` earlier and throw around some void pointers so we only
have to do it in one place.

Change-Id: I1d5462eb9a448147a95dd4ec50361b3f5a28910c
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/22786
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Reviewed-by: Philipp Deppenwiese <zaolin.daisuki@gmail.com>

util/crossgcc/patches/gcc-6.3.0_ada-musl_workaround.patch

@@ -0,0 +1,118 @@
+diff -urp gcc-6.3.0.bak/gcc/ada/adaint.c gcc-6.3.0/gcc/ada/adaint.c
+--- gcc-6.3.0.bak/gcc/ada/adaint.c	2017-12-08 20:39:08.024709803 +0000
++++ gcc-6.3.0/gcc/ada/adaint.c	2017-12-08 20:06:13.674636566 +0000
+@@ -103,6 +103,15 @@
+ #define xmalloc(S) malloc (S)
+ #define xrealloc(V,S) realloc (V,S)
+ #else
++#if !defined(__ANDROID__) && defined(__linux__)
++#ifdef __cplusplus
++extern "C" {
++#endif
++#include <sched.h>
++#ifdef __cplusplus
++}
++#endif
++#endif
+ #include "config.h"
+ #include "system.h"
+ #include "version.h"
+@@ -3096,7 +3105,7 @@ __gnat_lwp_self (void)
+ 
+ /* Dynamic cpu sets */
+ 
+-cpu_set_t *
++void *
+ __gnat_cpu_alloc (size_t count)
+ {
+   return CPU_ALLOC (count);
+@@ -3109,33 +3118,33 @@ __gnat_cpu_alloc_size (size_t count)
+ }
+ 
+ void
+-__gnat_cpu_free (cpu_set_t *set)
++__gnat_cpu_free (void *set)
+ {
+-  CPU_FREE (set);
++  CPU_FREE ((cpu_set_t *)set);
+ }
+ 
+ void
+-__gnat_cpu_zero (size_t count, cpu_set_t *set)
++__gnat_cpu_zero (size_t count, void *set)
+ {
+   CPU_ZERO_S (count, set);
+ }
+ 
+ void
+-__gnat_cpu_set (int cpu, size_t count, cpu_set_t *set)
++__gnat_cpu_set (int cpu, size_t count, void *set)
+ {
+   /* Ada handles CPU numbers starting from 1, while C identifies the first
+      CPU by a 0, so we need to adjust. */
+-  CPU_SET_S (cpu - 1, count, set);
++  CPU_SET_S (cpu - 1, count, (cpu_set_t *)set);
+ }
+ 
+ #else /* !CPU_ALLOC */
+ 
+ /* Static cpu sets */
+ 
+-cpu_set_t *
++void *
+ __gnat_cpu_alloc (size_t count ATTRIBUTE_UNUSED)
+ {
+-  return (cpu_set_t *) xmalloc (sizeof (cpu_set_t));
++  return xmalloc (sizeof (cpu_set_t));
+ }
+ 
+ size_t
+@@ -3145,23 +3154,23 @@ __gnat_cpu_alloc_size (size_t count ATTR
+ }
+ 
+ void
+-__gnat_cpu_free (cpu_set_t *set)
++__gnat_cpu_free (void *set)
+ {
+   free (set);
+ }
+ 
+ void
+-__gnat_cpu_zero (size_t count ATTRIBUTE_UNUSED, cpu_set_t *set)
++__gnat_cpu_zero (size_t count ATTRIBUTE_UNUSED, void *set)
+ {
+   CPU_ZERO (set);
+ }
+ 
+ void
+-__gnat_cpu_set (int cpu, size_t count ATTRIBUTE_UNUSED, cpu_set_t *set)
++__gnat_cpu_set (int cpu, size_t count ATTRIBUTE_UNUSED, void *set)
+ {
+   /* Ada handles CPU numbers starting from 1, while C identifies the first
+      CPU by a 0, so we need to adjust. */
+-  CPU_SET (cpu - 1, set);
++  CPU_SET (cpu - 1, (cpu_set_t *)set);
+ }
+ #endif /* !CPU_ALLOC */
+ #endif /* __linux__ */
+diff -urp gcc-6.3.0.bak/gcc/ada/adaint.h gcc-6.3.0/gcc/ada/adaint.h
+--- gcc-6.3.0.bak/gcc/ada/adaint.h	2017-12-08 20:39:08.024709803 +0000
++++ gcc-6.3.0/gcc/ada/adaint.h	2017-12-08 19:52:31.627939406 +0000
+@@ -287,13 +287,11 @@ extern void   *__gnat_lwp_self			   (voi
+ 
+ /* Routines for interface to required CPU set primitives */
+ 
+-#include <sched.h>
+-
+-extern cpu_set_t *__gnat_cpu_alloc                 (size_t);
++extern void *__gnat_cpu_alloc                 (size_t);
+ extern size_t __gnat_cpu_alloc_size                (size_t);
+-extern void   __gnat_cpu_free                  (cpu_set_t *);
+-extern void   __gnat_cpu_zero                      (size_t, cpu_set_t *);
+-extern void   __gnat_cpu_set                       (int, size_t, cpu_set_t *);
++extern void   __gnat_cpu_free                  (void *);
++extern void   __gnat_cpu_zero                      (size_t, void *);
++extern void   __gnat_cpu_set                       (int, size_t, void *);
+ #endif
+ 
+ #if defined (_WIN32)