Const propagation often marks terminator operands as constant

Author: oli-obk

src/librustc_mir/transform/mod.rs

@@ -256,6 +256,7 @@ fn optimized_mir<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, def_id: DefId) -> &'tcx
         // Optimizations begin.
         inline::Inline,
         instcombine::InstCombine,
+        simplify_branches::SimplifyBranches::new("after-const-prop"),
         deaggregator::Deaggregator,
         copy_prop::CopyPropagation,
         remove_noop_landing_pads::RemoveNoopLandingPads,