Remove s_assert definition from ircd_defs.h and add it to its own header.

s_assert requires some higher-level functionality that shouldn't be
present in ircd_defs.h. ircd_defs.h is used by ssld, which has no notion
of logging or sending IRC messages. Additionally, some of the headers
s_assert depends on result in conflicting definitions in ssld.c.

This change also fixes the compile when using --enable-assert=soft.

modules/core/m_ban.c

@@ -44,6 +44,7 @@
 #include "operhash.h"
 #include "reject.h"
 #include "hostmask.h"
+#include "logger.h"
 
 static int m_ban(struct Client *client_p, struct Client *source_p, int parc, const char *parv[]);
 static int ms_ban(struct Client *client_p, struct Client *source_p, int parc, const char *parv[]);

modules/core/m_join.c

@@ -42,6 +42,7 @@
 #include "packet.h"
 #include "chmode.h"
 #include "ratelimit.h"
+#include "s_assert.h"
 
 static int m_join(struct Client *, struct Client *, int, const char **);
 static int ms_join(struct Client *, struct Client *, int, const char **);

modules/core/m_nick.c

@@ -47,6 +47,7 @@
 #include "scache.h"
 #include "s_newconf.h"
 #include "monitor.h"
+#include "s_assert.h"
 
 /* Give all UID nicks the same TS. This ensures nick TS is always the same on
  * all servers for each nick-user pair, also if a user with a UID nick changes