irc/unreal: fix inline which should be static

During an exp-run for llvm 13 (see bug 258209), it turned out that
irc/unreal fails to build with clang 13:

cc -I../include -I@TREINCDIR@ -I/wrkdirs/usr/ports/irc/unreal/work/Unreal3.2.10.7/extras/regexp/include -pipe -O2 -pipe  -I/usr/local/include -fcommon -fstack-protector-strong -fno-strict-aliasing  -funsigned-char -Wl,-export-dynamic  -L/usr/local/lib  -fstack-protector-strong   -lssl -lcrypto -o ircd timesynch.o res.o s_bsd.o auth.o aln.o channel.o cloak.o crule.o dbuf.o  events.o fdlist.o hash.o help.o ircd.o ircsprintf.o list.o lusers.o  match.o modules.o packet.o parse.o s_auth.o  s_conf.o s_debug.o s_err.o s_extra.o s_kline.o  s_misc.o s_numeric.o s_serv.o s_svs.o  socket.o  ssl.o s_user.o charsys.o scache.o send.o support.o umodes.o  version.o whowas.o zip.o cidr.o random.o extcmodes.o  extbans.o md5.o api-isupport.o api-command.o  -L/usr/local/lib  -fstack-protector-strong  -lcrypt  /wrkdirs/usr/ports/irc/unreal/work/Unreal3.2.10.7/extras/regexp/lib/libtre.a   -L/usr/local/lib -fstack-protector-strong  -L/usr/local/lib -lcares -lssl -lcrypto
ld: error: undefined symbol: parse_addlag
>>> referenced by parse.c
>>>               parse.o:(parse)
>>> referenced by parse.c
>>>               parse.o:(parse)
cc: error: linker command failed with exit code 1 (use -v to see invocation)
*** Error code 1

This is because parse_addlag() is marked as 'inline' but does not have
either 'static' or 'extern' specifiers. Add a 'static' specifier to
resolve the link error.

PR:		258472
Approved by:	maintainer timeout (2 weeks)
MFH:		2021Q4

irc/unreal/files/patch-src_parse.c

@@ -0,0 +1,11 @@
+--- src/parse.c.orig	2016-09-03 19:34:06 UTC
++++ src/parse.c
+@@ -156,7 +156,7 @@ void ban_flooder(aClient *cptr)
+ /*
+  * This routine adds fake lag if needed.
+  */
+-inline void parse_addlag(aClient *cptr, int cmdbytes)
++static inline void parse_addlag(aClient *cptr, int cmdbytes)
+ {
+ 	if (!IsServer(cptr) && !IsNoFakeLag(cptr) &&
+ #ifdef FAKELAG_CONFIGURABLE