all: fix wildcard to work with make-4.x

In make-3.8x, the $(wildacrd) function would sort the entries,
while in make-4.x, it would just return the entries in any
unpredictable order [*]

Use the $(sort) function to get reproducible behaviour.

[*] Well, most probably the roder the entries appear when read
from readdir()

Reported-by: Andrew Ruder <andrew.ruder@elecsyscorp.com>
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Tested-by: Andrew Ruder <andrew.ruder@elecsyscorp.com>

diff -ru gdb-6.8.orig/bfd/sysdep.h gdb-6.8/bfd/sysdep.h

--- gdb-6.8.orig/bfd/sysdep.h	2007-07-03 16:26:42.000000000 +0200

+++ gdb-6.8/bfd/sysdep.h	2011-08-21 13:33:47.000000000 +0200

@@ -131,7 +131,7 @@

 extern PTR realloc ();

 #endif

-#if !HAVE_DECL_STPCPY

+#if !HAVE_DECL_STPCPY && !defined(stpcpy)

 extern char *stpcpy (char *__dest, const char *__src);

 #endif