Start new design for interceptors and implement String.charCodeAt with it.

sdk/lib/_internal/compiler/implementation/resolution/members.dart

 // Copyright (c) 2012, 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 resolution;
 
 abstract class TreeElements {
   Element operator[](Node node);
   Selector getSelector(Send send);
   DartType getType(Node node);
@@ skipping 1839 matching lines @@
   visitLiteralInt(LiteralInt node) {
   }
 
   visitLiteralDouble(LiteralDouble node) {
   }
 
   visitLiteralBool(LiteralBool node) {
   }
 
   visitLiteralString(LiteralString node) {
+    world.registerInstantiatedClass(compiler.stringClass);
   }
 
   visitLiteralNull(LiteralNull node) {
   }
 
   visitStringJuxtaposition(StringJuxtaposition node) {
+    world.registerInstantiatedClass(compiler.stringClass);
     node.visitChildren(this);
   }
 
   visitNodeList(NodeList node) {
     for (Link<Node> link = node.nodes; !link.isEmpty; link = link.tail) {
       visit(link.head);
     }
   }
 
   visitOperator(Operator node) {
@@ skipping 191 matching lines @@
       }
     }
     visit(node.elements);
   }
 
   visitConditional(Conditional node) {
     node.visitChildren(this);
   }
 
   visitStringInterpolation(StringInterpolation node) {
+    world.registerInstantiatedClass(compiler.stringClass);
     node.visitChildren(this);
   }
 
   visitStringInterpolationPart(StringInterpolationPart node) {
     registerImplicitInvocation(const SourceString('toString'), 0);
     node.visitChildren(this);
   }
 
   visitBreakStatement(BreakStatement node) {
     TargetElement target;
@@ skipping 515 matching lines @@
                              new NodeList.empty(),
                              new Block(new NodeList.empty()),
                              null, Modifiers.EMPTY, null, null);
   }
 
   isBlackListed(DartType type) {
     LibraryElement lib = element.getLibrary();
     return
       !identical(lib, compiler.coreLibrary) &&
       !identical(lib, compiler.jsHelperLibrary) &&
+      !identical(lib, compiler.interceptorsLibrary) &&
       (identical(type.element, compiler.dynamicClass) ||
        identical(type.element, compiler.boolClass) ||
        identical(type.element, compiler.numClass) ||
        identical(type.element, compiler.intClass) ||
        identical(type.element, compiler.doubleClass) ||
        identical(type.element, compiler.stringClass) ||
        identical(type.element, compiler.nullClass) ||
        identical(type.element, compiler.functionClass));
   }
 }
@@ skipping 447 matching lines @@
     return e;
   }
 
   /// Assumed to be called by [resolveRedirectingFactory].
   Element visitReturn(Return node) {
     Node expression = node.expression;
     return finishConstructorReference(visit(expression),
                                       expression, expression);
   }
 }