Function rustc_trait_selection::solve::project_goals::fetch_eligible_assoc_item_def

fn fetch_eligible_assoc_item_def<'tcx>(
    ecx: &EvalCtxt<'_, 'tcx>,
    param_env: ParamEnv<'tcx>,
    goal_trait_ref: TraitRef<'tcx>,
    trait_assoc_def_id: DefId,
    impl_def_id: DefId
) -> Result<Option<LeafDef>, NoSolution>

This behavior is also implemented in rustc_ty_utils and in the old project code.

FIXME: We should merge these 3 implementations as it’s likely that they otherwise diverge.