stage1 支持label break, continue

stage1/spl_sema.h

@@ -49,6 +49,7 @@ typedef struct {
     spl_attr_t *attr;
     spl_lang_type_id_t current_aggregate_lang;
     spl_lang_type_id_t current_fn_ret_tid;
+    spl_symbol_path_t label_stack;
 } spl_sema_t;
 
 void spl_sema_init(spl_sema_t *sema, spl_ast_t *ast, spl_type_t *type, spl_scope_t *scope,