headers: properly decorate attributes

Found by:
find -name '*.h' |xargs grep -i 'attribute.*(([a-z]'

For an example of the type of bugs this causes, try compiling this valid
C11 program (it's valid because 'noreturn' is reserved for use in the
user namespace unless you include <stdnoreturn.h>):

$ cat foo.c
#define noreturn __attribute__((noreturn))
#include <stdlib.h>
$ gcc -c -o foo.o -Wall foo.c
In file included from /usr/include/stdlib.h:11:0,
                 from foo.c:2:
foo.c:1:18: error: expected ')' before '__attribute__'
 #define noreturn __attribute__((noreturn))
                  ^
/usr/include/stdlib.h:66:28: error: expected ',' or ';' before ')' token
 _VOID _EXFUN(abort,(_VOID) _ATTRIBUTE ((noreturn)));
                            ^

* libc/machine/spu/spu_timer_internal.h: Decorate attribute names
with __, for namespace safety.
* libc/machine/xscale/machine/profile.h: Likewise.
* libc/include/stdlib.h: Likewise.
* libc/include/_ansi.h: Likewise.
* libc/include/sys/unistd.h: Likewise.
* libc/sys/linux/linuxthreads/libc-symbols.h: Likewise.
* libc/sys/linux/linuxthreads/internals.h: Likewise.
* libc/sys/linux/machine/i386/weakalias.h: Likewise.
* libc/sys/linux/machine/i386/dl-procinfo.h: Likewise.
* libc/sys/linux/machine/i386/dl-machine.h: Likewise.
* libc/sys/linux/libc-symbols.h: Likewise.
* libc/sys/linux/iconv/gconv_charset.h: Likewise.
* libc/sys/linux/include/resolv.h: Likewise.
* libc/sys/linux/sys/unistd.h: Likewise.
* libc/sys/linux/dl/atomicity.h: Likewise.
* libc/sys/linux/dl/dynamic-link.h: Likewise.
* libc/sys/linux/dl/ldsodefs.h: Likewise.

1 files changed, 1 insertions, 1 deletions

diff --git a/newlib/libc/sys/linux/dl/ldsodefs.h b/newlib/libc/sys/linux/dl/ldsodefs.h
index e6f57ddcf..8cf487ad9 100644
--- a/newlib/libc/sys/linux/dl/ldsodefs.h
+++ b/newlib/libc/sys/linux/dl/ldsodefs.h
@@ -162,7 +162,7 @@ struct libname_list
 
 /* Test whether given NAME matches any of the names of the given object.  */
 static __inline int
-__attribute__ ((unused))
+__attribute__ ((__unused__))
 _dl_name_match_p (const char *__name, struct link_map *__map)
 {
   int __found = strcmp (__name, __map->l_name) == 0;