syntax_data: {"ast_node_type":"variable","tokens":[{"end":47,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:                 let yield_ty = args.type_at(0);
context_before:                 let ty::Adt(_option_adt, args) = *args.type_at(0).kind() else { bug!() };
context_after:                 Rvalue::Use(Operand::Constant(Box::new(ConstOperand {