syntax_data: {"ast_node_type":"variable","tokens":[{"end":76,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:     let pin_fut_bb = body.basic_blocks_mut().push(BasicBlockData::new_stmts(
context_before:     // call Pin<FutTy>::new_unchecked(&mut fut)
context_after:         [storage_live, fut_ref_assign].to_vec(),