Function rustc_mir_transform::mir_const

pub(crate) fn mir_const<'tcx>(
    tcx: TyCtxt<'tcx>,
    def: WithOptConstParam<LocalDefId>
) -> &'tcx Steal<Body<'tcx>>

Make MIR ready for const evaluation. This is run on all MIR, not just on consts! FIXME(oli-obk): it’s unclear whether we still need this phase (and its corresponding query). We used to have this for pre-miri MIR based const eval.