lang: ast: add a BLOCK ast node to hold lists of expressions

lang/ast/node.h

@@ -12,6 +12,7 @@ struct parser_state;
 #define PARSE_RESULT(status, flags)                                            \
 	((struct token_parse_result) {.r_status = (status), .r_flags = (flags)})
 
+
 enum token_parse_flags {
 	PARSE_REPEAT_TOKEN = 0x01u,
 };