prevented a syncoded symbol from being used as a variable/argument name

hcl/lib/main.c

@@ -596,6 +596,8 @@ static char* syntax_error_msg[] =
 	"too many variables defined",
 	"variable declaration disallowed",
 	"duplicate variable name",
+	"disallowed variable name",
+	"disallowed argument name",
 
 	"break outside loop"
 };