Function emit_drop_facts 

pub(crate) fn emit_drop_facts<'tcx>(
    tcx: TyCtxt<'tcx>,
    local: Local,
    kind: &GenericArg<'tcx>,
    universal_regions: &UniversalRegions<'tcx>,
    facts: &mut Option<PoloniusFacts>,
)

For every potentially drop()-touched region region in local’s type (kind), emit a drop_of_var_derefs_origin(local, origin) fact.