GVN getInterceptor and use the interceptor constant when the type is known.

sdk/lib/_internal/compiler/implementation/js_backend/backend.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 js_backend;
 
 typedef void Recompile(Element element);
 
 class ReturnInfo {
   HType returnType;
@@ skipping 640 matching lines @@
   ClassElement jsNumberClass;
   ClassElement jsIntClass;
   ClassElement jsDoubleClass;
   ClassElement jsFunctionClass;
   ClassElement jsNullClass;
   ClassElement jsBoolClass;
   ClassElement objectInterceptorClass;
   Element jsArrayLength;
   Element jsStringLength;
   Element getInterceptorMethod;
+  Element arrayInterceptor;
+  Element boolInterceptor;
+  Element doubleInterceptor;
+  Element functionInterceptor;
+  Element intInterceptor;
+  Element nullInterceptor;
+  Element numberInterceptor;
+  Element stringInterceptor;
   bool _interceptorsAreInitialized = false;
 
   final Namer namer;
 
   /**
    * Interface used to determine if an object has the JavaScript
    * indexing behavior. The interface is only visible to specific
    * libraries.
    */
   ClassElement jsIndexingBehaviorInterface;
@@ skipping 110 matching lines @@
     jsFunctionClass =
         compiler.findInterceptor(const SourceString('JSFunction'));
     jsBoolClass =
         compiler.findInterceptor(const SourceString('JSBool'));
     jsArrayClass.ensureResolved(compiler);
     jsArrayLength =
         jsArrayClass.lookupLocalMember(const SourceString('length'));
     jsStringClass.ensureResolved(compiler);
     jsStringLength =
         jsStringClass.lookupLocalMember(const SourceString('length'));
+
+    arrayInterceptor =
+        compiler.findInterceptor(const SourceString('arrayInterceptor'));
+    boolInterceptor =
+        compiler.findInterceptor(const SourceString('boolInterceptor'));
+    doubleInterceptor =
+        compiler.findInterceptor(const SourceString('doubleInterceptor'));
+    functionInterceptor =
+        compiler.findInterceptor(const SourceString('functionInterceptor'));
+    intInterceptor =
+        compiler.findInterceptor(const SourceString('intInterceptor'));
+    nullInterceptor =
+        compiler.findInterceptor(const SourceString('nullInterceptor'));
+    stringInterceptor =
+        compiler.findInterceptor(const SourceString('stringInterceptor'));
+    numberInterceptor =
+        compiler.findInterceptor(const SourceString('numberInterceptor'));
   }
 
   void addInterceptors(ClassElement cls) {
     cls.ensureResolved(compiler);
     cls.forEachMember((ClassElement classElement, Element member) {
         Set<Element> set = interceptedElements.putIfAbsent(
             member.name, () => new Set<Element>());
         set.add(member);
       },
       includeSuperMembers: true);
@@ skipping 299 matching lines @@
     print("Inferred return types:");
     print("----------------------");
     dumpReturnTypes();
     print("");
     print("Inferred field types:");
     print("------------------------");
     fieldTypes.dump();
     print("");
   }
 }