patch 8.2.3503: Vim9: using g:pat:cmd is confusing

Problem:    Vim9: using g:pat:cmd is confusing.
Solution:   Do not recognize g: as the :global command.  Also for s:pat:repl.
            (closes #8982)
diff --git a/src/errors.h b/src/errors.h
index 4cc50e4..a2a1394 100644
--- a/src/errors.h
+++ b/src/errors.h
@@ -666,3 +666,7 @@
 	INIT(= N_("E1239: Invalid value for blob: %d"));
 EXTERN char e_resulting_text_too_long[]
 	INIT(= N_("E1240: Resulting text too long"));
+EXTERN char e_separator_not_supported_str[]
+	INIT(= N_("E1241: Separator not supported: %s"));
+EXTERN char e_no_white_space_allowed_before_separator_str[]
+	INIT(= N_("E1242: No white space allowed before separator: %s"));