syntax_data: {"ast_node_type":"other","tokens":[{"end":42,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:                 // Compute Poll<return_ty>
context_before:             CoroutineKind::Desugared(CoroutineDesugaring::Async, _) => {
context_after:                 let poll_did = tcx.require_lang_item(LangItem::Poll, body.span);