syntax_data: {"ast_node_type":"other","tokens":[{"end":22,"kind":"keyword","start":0,"text":"tcx:"}]}
source_snippet:     tcx: TyCtxt<'tcx>,
context_before: struct Builder<'a, 'tcx> {
context_after:     // FIXME(@lcnr): Why does this use an `infcx`, there should be