gcc: fix conflicting prototype of posix_memalign for C++

Ref: http://www.openwall.com/lists/musl/2013/11/10/1.

This patch is required for building cups-filters, libvisio, libcdr and
probably many more with musl.

srcpkgs/gcc/patches/musl-posix_memalign-c++.patch

@@ -0,0 +1,30 @@
+diff --git gcc/config/i386/pmm_malloc.h gcc/config/i386/pmm_malloc.h
+index 901001b..321fcd3 100644
+--- gcc/config/i386/pmm_malloc.h
++++ gcc/config/i386/pmm_malloc.h
+@@ -27,12 +27,13 @@
+ #include <stdlib.h>
+
+ /* We can't depend on <stdlib.h> since the prototype of posix_memalign
+-   may not be visible.  */
++   may not be visible and we can't pollute the namespace either.  */
+ #ifndef __cplusplus
+-extern int posix_memalign (void **, size_t, size_t);
++extern int __gcc_posix_memalign (void **, size_t, size_t)
+ #else
+-extern "C" int posix_memalign (void **, size_t, size_t) throw ();
++extern "C" int __gcc_posix_memalign (void **, size_t, size_t) throw ()
+ #endif
++__asm__("posix_memalign");
+
+ static __inline void *
+ _mm_malloc (size_t size, size_t alignment)
+@@ -42,7 +43,7 @@  _mm_malloc (size_t size, size_t alignment)
+     return malloc (size);
+   if (alignment == 2 || (sizeof (void *) == 8 && alignment == 4))
+     alignment = sizeof (void *);
+-  if (posix_memalign (&ptr, alignment, size) == 0)
++  if (__gcc_posix_memalign (&ptr, alignment, size) == 0)
+     return ptr;
+   else
+     return NULL;

srcpkgs/gcc/template

@@ -2,7 +2,7 @@
 pkgname=gcc
 _majorver=4.9
 version=${_majorver}.2
-revision=7
+revision=8
 short_desc="The GNU C Compiler"
 maintainer="Juan RP <xtraeme@voidlinux.eu>"
 homepage="http://gcc.gnu.org"