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/gui_mac.c b/src/gui_mac.c
index ec8ec3a..cd27bb4 100644
--- a/src/gui_mac.c
+++ b/src/gui_mac.c
@@ -3556,7 +3556,7 @@
     if (font == NOFONT)
     {
 	if (giveErrorIfMissing)
-	    EMSG2(_(e_font), name);
+	    semsg(_(e_font), name);
 	return NOFONT;
     }
     /*