Move dart2js from sdk/lib/_internal/compiler to pkg/compiler

tests/compiler/dart2js/backend_dart/opt_redundant_phi_test.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // 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.
 
 import 'sexpr_unstringifier.dart';
 import "package:expect/expect.dart";
-import 'package:compiler/implementation/cps_ir/cps_ir_nodes.dart';
-import 'package:compiler/implementation/cps_ir/cps_ir_nodes_sexpr.dart';
-import 'package:compiler/implementation/cps_ir/optimizers.dart';
+import 'package:compiler/src/cps_ir/cps_ir_nodes.dart';
+import 'package:compiler/src/cps_ir/cps_ir_nodes_sexpr.dart';
+import 'package:compiler/src/cps_ir/optimizers.dart';
 
 // The 'read in loop' IR tests the most basic case of redundant phi removal
 // and represents the following source code:
 //
 // void main() {
 //   int j = 42;
 //   for (int i = 0; i < 2; i++) {
 //     print(j.toString());
 //   }
 // }
@@ skipping 230 matching lines @@
 
 void main() {
   testRedundantPhi(READ_IN_LOOP_IN, READ_IN_LOOP_OUT);
   testRedundantPhi(INNER_LOOP_IN, INNER_LOOP_OUT);
   testRedundantPhi(BASIC_LOOP_IN, BASIC_LOOP_OUT);
   testRedundantPhi(SCOPING_IN, SCOPING_OUT);
   testRedundantPhi(NEVER_INVOKED1_IN, NEVER_INVOKED1_OUT);
   testRedundantPhi(NEVER_INVOKED2_IN, NEVER_INVOKED2_OUT);
   testRedundantPhi(AS_ARG_IN, AS_ARG_OUT);
 }