Move all the builtin$ interceptors to a new interceptors library and shorten the names of them.

lib/compiler/implementation/elements/elements.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.
 
 #library('elements');
 
 #import('../tree/tree.dart');
 #import('../scanner/scannerlib.dart');
 #import('../leg.dart');  // TODO(karlklose): we only need type.
 #import('../util/util.dart');
@@ skipping 283 matching lines @@
       addGetterOrSetter(element, elements[element.name], listener);
     } else {
       Element existing = elements.putIfAbsent(element.name, () => element);
       if (existing !== element) {
         listener.cancel('duplicate definition', token: element.position());
         listener.cancel('existing definition', token: existing.position());
       }
     }
   }
 
+  /** Look up a top-level element in this library. The element could
+    * potentially have been imported from another library. Returns
+    * null if no such element exist. */
   Element find(SourceString elementName) {
     return elements[elementName];
   }
 
+  /** Look up a top-level element in this library, but only look for
+    * non-imported elements. Returns null if no such element exist. */
+  Element findLocal(SourceString elementName) {
+    Element result = elements[elementName];
+    if (result === null || result.getLibrary() != this) return null;
+    return result;
+  }
+
   void forEachExport(f(Element element)) {
     elements.forEach((SourceString _, Element e) {
       if (this === e.getLibrary()
           && e.kind !== ElementKind.PREFIX
           && e.kind !== ElementKind.FOREIGN) {
         if (!e.name.isPrivate()) f(e);
       }
     });
   }
 
@@ skipping 728 matching lines @@
   final Node node;
   Type bound;
   Type type;
   TypeVariableElement(name, Element enclosing, this.node, this.type,
                       [this.bound])
     : super(name, ElementKind.TYPE_VARIABLE, enclosing);
   Type computeType(compiler) => type;
   Node parseNode(compiler) => node;
   toString() => "${enclosingElement.toString()}.${name.slowToString()}";
 }