Function rustc_mir::transform::promoted_mir

fn promoted_mir<'tcx>(
    tcx: TyCtxt<'tcx>, 
    def: WithOptConstParam<LocalDefId>
) -> &'tcx IndexVec<Promoted, Body<'tcx>>

Fetch all the promoteds of an item and prepare their MIR bodies to be ready for constant evaluation once all substitutions become known.