{"ast_node_type":"other","tokens":[{"end":87,"kind":"keyword","start":0,"text":"//"}]}
        // `while` before reaching it, as block tail returns are not available in them.
        // Get enclosing Fn, if it is a function or a trait method, unless there's a `loop` or
        self.tcx.hir_get_fn_id_for_return_block(blk_id).and_then(|item_id| {