dart2js cps: Add path-sensitive types by inserting refinement IR nodes.

pkg/compiler/lib/src/cps_ir/optimizers.dart

Index: pkg/compiler/lib/src/cps_ir/optimizers.dart
diff --git a/pkg/compiler/lib/src/cps_ir/optimizers.dart b/pkg/compiler/lib/src/cps_ir/optimizers.dart
index 11c9fae5708867fb92c7c0c0ac94b0ddfbad034d..5cf609970f1abd5525739c5365b174490fc457a7 100644
--- a/pkg/compiler/lib/src/cps_ir/optimizers.dart
+++ b/pkg/compiler/lib/src/cps_ir/optimizers.dart
@@ -14,6 +14,8 @@ export 'redundant_join.dart' show RedundantJoinEliminator;
 export 'shrinking_reductions.dart' show ShrinkingReducer, ParentVisitor;
 export 'mutable_ssa.dart' show MutableVariableEliminator;
 export 'let_sinking.dart' show LetSinker;
+export 'insert_refinements.dart' show InsertRefinements;
+export 'remove_refinements.dart' show RemoveRefinements;
 export 'loop_invariant_code_motion.dart' show LoopInvariantCodeMotion;
 export 'share_interceptors.dart' show ShareInterceptors;