patch 8.2.3162: Vim9: argument types are not checked at compile time

Problem:    Vim9: argument types are not checked at compile time.
Solution:   Add more type checks. (Yegappan Lakshmanan, closes #8560)
diff --git a/src/terminal.c b/src/terminal.c
index 9de516c..9db0475 100644
--- a/src/terminal.c
+++ b/src/terminal.c
@@ -5689,6 +5689,11 @@
 	{"reverse",   HL_INVERSE},
     };
 
+    if (in_vim9script()
+	    && (check_for_number_arg(argvars, 0) == FAIL
+		|| check_for_string_arg(argvars, 1) == FAIL))
+	return;
+
     attr = tv_get_number(&argvars[0]);
     name = tv_get_string_chk(&argvars[1]);
     if (name == NULL)