tools/bc: let getopt() prototype be defined normally

Add a patch in order to remove an obsolete workaround
that is currently causing issues on some macOS systems.

Add patch:
 - 000-getopt-prototype.patch

Tested-by: Georgi Valkov <gvalkov@gmail.com> # macOS
Signed-off-by: Michael Pratt <mcpratt@pm.me>
Link: https://github.com/openwrt/openwrt/pull/16522
Signed-off-by: Robert Marko <robimarko@gmail.com>

tools/bc/patches/000-getopt-prototype.patch

@@ -0,0 +1,18 @@
+--- a/h/getopt.h
++++ b/h/getopt.h
+@@ -135,15 +135,7 @@ struct option
+    arguments to the option '\0'.  This behavior is specific to the GNU
+    `getopt'.  */
+ 
+-#ifdef __GNU_LIBRARY__
+-/* Many other libraries have conflicting prototypes for getopt, with
+-   differences in the consts, in stdlib.h.  To avoid compilation
+-   errors, only prototype getopt for the GNU C library.  */
+ extern int getopt (int ___argc, char *const *___argv, const char *__shortopts);
+-#else /* not __GNU_LIBRARY__ */
+-extern int getopt ();
+-#endif /* __GNU_LIBRARY__ */
+-
+ #ifndef __need_getopt
+ extern int getopt_long (int ___argc, char *const *___argv,
+ 			const char *__shortopts,