Use loc to fix a failure of test_ast.rb

```
    1) Failure:
  TestAst#test_ranges:test/fiber/scheduler.rb [/home/runner/work/ruby/ruby/src/test/ruby/test_ast.rb:122]:
  <[]> expected but was
  <[{:type=>:max_validation_error,
    :max=>
     #<RubyVM::AbstractSyntaxTree::Node::CodePosition:0x00007f80d630b598
      @column=20,
      @lineno=203>,
    :end_pos=>
     #<RubyVM::AbstractSyntaxTree::Node::CodePosition:0x00007f80d630b778
      @column=19,
      @lineno=203>,
    :node=>
     (BLOCK_PASS@203:15-203:19
        (ARGSPUSH@203:15-203:20 (SPLAT@203:16-203:19 (LVAR@203:16-203:19 :*))
           (HASH@203:16-203:19
              (LIST@203:16-203:19 nil (LVAR@203:16-203:19 :**) nil)))
        (LVAR@203:16-203:19 :&))}]>.
```

parse.y

@@ -13279,7 +13279,7 @@ new_args_forward_call(struct parser_params *p, NODE *leading, const YYLTYPE *loc
     NODE *kwrest = list_append(p, NEW_LIST(0, loc), NEW_LVAR(idFWD_KWREST, loc));
     NODE *block = NEW_BLOCK_PASS(NEW_LVAR(idFWD_BLOCK, loc), loc);
     NODE *args = leading ? rest_arg_append(p, leading, rest, argsloc) : NEW_SPLAT(rest, loc);
-    args = arg_append(p, args, new_hash(p, kwrest, loc), argsloc);
+    args = arg_append(p, args, new_hash(p, kwrest, loc), loc);
     return arg_blk_pass(args, block);
 }
 #endif