patch 8.1.0743: giving error messages is not flexible

Problem:    Giving error messages is not flexible.
Solution:   Add semsg().  Change argument from "char_u *" to "char *", also
            for msg() and get rid of most MSG macros. (Ozaki Kiichi, closes
            #3302)  Also make emsg() accept a "char *" argument.  Get rid of
            an enormous number of type casts.
diff --git a/src/hangulin.c b/src/hangulin.c
index 7512d95..e08fe63 100644
--- a/src/hangulin.c
+++ b/src/hangulin.c
@@ -588,7 +588,7 @@
 	    return AUTOMATA_CORRECT_NEW;
 
 	default:
-	    IEMSG(_("E256: Hangul automata ERROR"));
+	    iemsg(_("E256: Hangul automata ERROR"));
 	    break;
     }
     return AUTOMATA_ERROR; /* RrEeAaLlLlYy EeRrRrOoRr */