fn compute_definition_site_hidden_types_from_defining_uses<'tcx>(
rcx: &RegionCtxt<'_, 'tcx>,
hidden_types: &mut FxIndexMap<LocalDefId, DefinitionSiteHiddenType<'tcx>>,
defining_uses: &[DefiningUse<'tcx>],
errors: &mut Vec<DeferredOpaqueTypeError<'tcx>>,
)