patch 8.2.3734: Vim9: crash when no pattern match found

Problem:    Vim9: crash when no pattern match found.
Solution:   Check for error.
diff --git a/src/vim9execute.c b/src/vim9execute.c
index bd7f71e..2908e55 100644
--- a/src/vim9execute.c
+++ b/src/vim9execute.c
@@ -1785,6 +1785,8 @@
 		    ea.addr_type = ADDR_LINES;
 		    ea.cmd = iptr->isn_arg.string;
 		    parse_cmd_address(&ea, &error, FALSE);
+		    if (ea.cmd == NULL)
+			goto on_error;
 		    if (error == NULL)
 			error = ex_range_without_command(&ea);
 		    if (error != NULL)