syntax_data: {"ast_node_type":"other","tokens":[{"end":93,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:     // Clean drop and async_fut fields if potentially async drop is not expanded (stays sync)
context_before:     let dropline = gather_dropline_blocks(body);
context_after:     let remove_asyncness = |block: &mut BasicBlockData<'tcx>| {