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

pkg/compiler/lib/src/types/forwarding_type_mask.dart

-// Copyright (c) 2013, 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.
-
-part of types;
-
-/**
- * A type mask that wraps an other one, and delegate all its
- * implementation methods to it.
- */
-abstract class ForwardingTypeMask implements TypeMask {
-
-  TypeMask get forwardTo;
-
-  ForwardingTypeMask();
-
-  bool get isEmpty => forwardTo.isEmpty;
-  bool get isNullable => forwardTo.isNullable;
-  bool get isExact => forwardTo.isExact;
-
-  bool get isUnion => false;
-  bool get isContainer => false;
-  bool get isMap => false;
-  bool get isDictionary => false;
-  bool get isValue => false;
-  bool get isForwarding => true;
-
-  bool isInMask(TypeMask other, ClassWorld classWorld) {
-    return forwardTo.isInMask(other, classWorld);
-  }
-
-  bool containsMask(TypeMask other, ClassWorld classWorld) {
-    return forwardTo.containsMask(other, classWorld);
-  }
-
-  bool containsOnlyInt(ClassWorld classWorld) {
-    return forwardTo.containsOnlyInt(classWorld);
-  }
-
-  bool containsOnlyDouble(ClassWorld classWorld) {
-    return forwardTo.containsOnlyDouble(classWorld);
-  }
-
-  bool containsOnlyNum(ClassWorld classWorld) {
-    return forwardTo.containsOnlyNum(classWorld);
-  }
-
-  bool containsOnlyBool(ClassWorld classWorld) {
-    return forwardTo.containsOnlyBool(classWorld);
-  }
-
-  bool containsOnlyString(ClassWorld classWorld) {
-    return forwardTo.containsOnlyString(classWorld);
-  }
-
-  bool containsOnly(ClassElement element) {
-    return forwardTo.containsOnly(element);
-  }
-
-  bool satisfies(ClassElement cls, ClassWorld classWorld) {
-    return forwardTo.satisfies(cls, classWorld);
-  }
-
-  bool contains(ClassElement type, ClassWorld classWorld) {
-    return forwardTo.contains(type, classWorld);
-  }
-
-  bool containsAll(ClassWorld classWorld) {
-    return forwardTo.containsAll(classWorld);
-  }
-
-  ClassElement singleClass(ClassWorld classWorld) {
-    return forwardTo.singleClass(classWorld);
-  }
-
-  TypeMask union(other, ClassWorld classWorld) {
-    if (this == other) {
-      return this;
-    } else if (equalsDisregardNull(other)) {
-      return other.isNullable ? other : this;
-    } else if (other.isEmpty) {
-      return other.isNullable ? this.nullable() : this;
-    }
-    return forwardTo.union(other, classWorld);
-  }
-
-  TypeMask intersection(TypeMask other, ClassWorld classWorld) {
-    return forwardTo.intersection(other, classWorld);
-  }
-
-  bool needsNoSuchMethodHandling(Selector selector, ClassWorld classWorld) {
-    return forwardTo.needsNoSuchMethodHandling(selector, classWorld);
-  }
-
-  bool canHit(Element element, Selector selector, ClassWorld classWorld) {
-    return forwardTo.canHit(element, selector, classWorld);
-  }
-
-  Element locateSingleElement(Selector selector, Compiler compiler) {
-    return forwardTo.locateSingleElement(selector, compiler);
-  }
-
-  bool equalsDisregardNull(other) {
-    if (other is! ForwardingTypeMask) return false;
-    if (forwardTo.isNullable) {
-      return forwardTo == other.forwardTo.nullable();
-    } else {
-      return forwardTo == other.forwardTo.nonNullable();
-    }
-  }
-
-  bool operator==(other) {
-    return equalsDisregardNull(other) && isNullable == other.isNullable;
-  }
-
-  int get hashCode => throw "Subclass should implement hashCode getter";
-}