optlist.h

Currently, options.c is the only file that #includes "optlist.h".

In theory, if a source file did want to include optlist.h (perhaps
for the struct allopt_t declaration so they could deal with a
pointer to such a struct), they wouldn't be able to include it
because of a static function prototype that it contains.

Add some protection to only include that static function
prototype when optlist.h is included from options.c.

src/options.c

@@ -50,6 +50,8 @@ NEARDATA struct instance_flags iflags; /* provide linkage */
  *
  */
 
+#define OPTIONS_C
+
 #define NHOPT_PROTO
 #include "optlist.h"
 #undef NHOPT_PROTO
@@ -72,6 +74,7 @@ static struct allopt_t allopt_init[] = {
 };
 #undef NHOPT_PARSE
 
+#undef OPTIONS_C
 
 #define PILE_LIMIT_DFLT 5
 #define rolestring(val, array, field) \