{"ast_node_type":"variable","tokens":[{"end":42,"kind":"keyword","start":0,"text":"let"}]}
    let typing_env = body.typing_env(tcx);
fn propagate_ssa<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) -> bool {
    let ssa = SsaLocals::new(tcx, body, typing_env);