Fix binding power for class <<

Author: kddnewton

src/prism.c

@@ -18379,7 +18379,7 @@ parse_expression_prefix(pm_parser_t *parser, pm_binding_power_t binding_power, b
 
             if (accept1(parser, PM_TOKEN_LESS_LESS)) {
                 pm_token_t operator = parser->previous;
-                pm_node_t *expression = parse_value_expression(parser, PM_BINDING_POWER_NOT, true, PM_ERR_EXPECT_EXPRESSION_AFTER_LESS_LESS);
+                pm_node_t *expression = parse_value_expression(parser, PM_BINDING_POWER_COMPOSITION, true, PM_ERR_EXPECT_EXPRESSION_AFTER_LESS_LESS);
 
                 pm_parser_scope_push(parser, true);
                 accept2(parser, PM_TOKEN_NEWLINE, PM_TOKEN_SEMICOLON);