{"ast_node_type":"other","tokens":[{"end":90,"kind":"keyword","start":0,"text":"CallTarget::Direct(func_ref)"}]}
            CallTarget::Direct(func_ref) => fx.bcx.func.dfg.ext_funcs[func_ref].signature,
        let sig_ref = match target {
            CallTarget::Indirect(sig_ref, _) => sig_ref,