Function rustc_trait_selection::traits::coherence::equate_impl_headers

fn equate_impl_headers<'tcx>(
    infcx: &InferCtxt<'tcx>,
    param_env: ParamEnv<'tcx>,
    impl1: &ImplHeader<'tcx>,
    impl2: &ImplHeader<'tcx>
) -> Option<PredicateObligations<'tcx>>