syntax_data: {"ast_node_type":"variable","tokens":[{"end":81,"kind":"keyword","start":0,"text":"if"}]}
source_snippet:         if let ty::ClauseKind::UnstableFeature(sym) = pred.kind().skip_binder() {
context_before:     for pred in param_env.caller_bounds().iter() {
context_after:             if sym == symbol {