parseopt: move definition of enum parse_opt_result up

Define enum parse_opt_result before using it in a typedef.  This avoids
the following compiler warning:

   ./parse-options.h:53:14: error: ISO C forbids forward references to 'enum' types [-Werror,-Wpedantic]
   typedef enum parse_opt_result parse_opt_ll_cb(struct parse_opt_ctx_t *ctx,
                ^

While GCC and Clang both accept such a forward reference by default,
other compilers might be less forgiving.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

parse-options.h

@@ -45,6 +45,15 @@ enum parse_opt_option_flags {
 	PARSE_OPT_COMP_ARG = 1024
 };
 
+enum parse_opt_result {
+	PARSE_OPT_COMPLETE = -3,
+	PARSE_OPT_HELP = -2,
+	PARSE_OPT_ERROR = -1,	/* must be the same as error() */
+	PARSE_OPT_DONE = 0,	/* fixed so that "return 0" works */
+	PARSE_OPT_NON_OPTION,
+	PARSE_OPT_UNKNOWN
+};
+
 struct option;
 typedef int parse_opt_cb(const struct option *, const char *arg, int unset);
 
@@ -224,15 +233,6 @@ const char *optname(const struct option *opt, int flags);
 
 /*----- incremental advanced APIs -----*/
 
-enum parse_opt_result {
-	PARSE_OPT_COMPLETE = -3,
-	PARSE_OPT_HELP = -2,
-	PARSE_OPT_ERROR = -1,	/* must be the same as error() */
-	PARSE_OPT_DONE = 0,	/* fixed so that "return 0" works */
-	PARSE_OPT_NON_OPTION,
-	PARSE_OPT_UNKNOWN
-};
-
 /*
  * It's okay for the caller to consume argv/argc in the usual way.
  * Other fields of that structure are private to parse-options and should not