Build new IR for functions returning a constant

sdk/lib/_internal/compiler/implementation/ir/ir.dart

Index: sdk/lib/_internal/compiler/implementation/ir/ir.dart
diff --git a/runtime/lib/function.dart b/sdk/lib/_internal/compiler/implementation/ir/ir.dart
similarity index 54%
copy from runtime/lib/function.dart
copy to sdk/lib/_internal/compiler/implementation/ir/ir.dart
index a75b564e41f0ad415bb8dd22d60b93f186face97..d1d75df7fc2c299ded4113c8d82ac95b883cbfaf 100644
--- a/runtime/lib/function.dart
+++ b/sdk/lib/_internal/compiler/implementation/ir/ir.dart
@@ -2,9 +2,12 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-class _FunctionImpl implements Function {
+library ir;
 
-  bool operator ==(other) native "FunctionImpl_equals";
+import '../elements/elements.dart';
+import '../dart2jslib.dart';
+import '../source_file.dart';
+import '../tree/tree.dart';
 
-  int get hashCode native "FunctionImpl_hashCode";
-}
+part 'inodes.dart';
+part 'inode_builder.dart';