fix res_mkquery and res_send prototypes in resolv.h

historically these functions appeared in BSD 4.3 without prototypes,
then in the bind project prototypes were added to resolv.h, but those
were incompatible with the definitions of the implementation.
the bind resolv.h became the defacto api most systems use now, but the
old internal definitions found their way into the linux manuals and thus
into musl.

include/resolv.h

@@ -125,14 +125,12 @@ struct res_sym {
 struct __res_state *__res_state(void);
 #define _res (*__res_state())
 
-struct rrec;
-
 int res_init(void);
 int res_query(const char *, int, int, unsigned char *, int);
 int res_querydomain(const char *, const char *, int, int, unsigned char *, int);
 int res_search(const char *, int, int, unsigned char *, int);
-int res_mkquery(int, const char *, int, int, char *, int, struct rrec *, char *, int);
-int res_send(const char *, int, char *, int);
+int res_mkquery(int, const char *, int, int, const unsigned char *, int, const unsigned char*, unsigned char *, int);
+int res_send(const unsigned char *, int, unsigned char *, int);
 int dn_comp(const char *, unsigned char *, int, unsigned char **, unsigned char **);
 int dn_expand(const unsigned char *, const unsigned char *, const unsigned char *, char *, int);
 int dn_skipname(const unsigned char *, const unsigned char *);