- Introduce `rb_parser_ary_t` structure to partly eliminate RArray from parse.y - In this patch, `parser_params->tokens` and `parser_params->ast->node_buffer->tokens` are now `rb_parser_ary_t *` - Instead, `ast_node_all_tokens()` internally creates a Ruby Array object from the `rb_parser_ary_t` - Also, delete `rb_ast_tokens()` and `rb_ast_set_tokens()` in node.c - Implement `rb_parser_str_escape()` - This is a port of the `rb_str_escape()` function in string.c - `rb_parser_str_escape()` does not depend on `VALUE` (RString) - Instead, it uses `rb_parser_stirng_t *` - This function works when --dump=y option passed - Because WIP of the universal parser, similar functions like `rb_parser_tokens_free()` exist in both node.c and parse.y. Refactoring them may be needed in some way in the future - Although we considered redesigning the structure: `ast->node_buffer->tokens` into `ast->tokens`, we leave it as it is because `rb_ast_t` is an imemo. (We will address it in the future)