Add version validation for LookupMap, also add unittest directly in LookupMap (take 2)

pkg/compiler/lib/src/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;
 
 const VERBOSE_OPTIMIZER_HINTS = false;
 
 class JavaScriptItemCompilationContext extends ItemCompilationContext {
   final Set<HInstruction> boundsChecked = new Set<HInstruction>();
@@ skipping 2141 matching lines @@
         preserveUrisMarker = find(library, 'preserveUris');
         preserveLibraryNamesMarker = find(library, 'preserveLibraryNames');
       } else if (uri == DART_JS_NAMES) {
         preserveNamesMarker = find(library, 'preserveNames');
       } else if (uri == DART_EMBEDDED_NAMES) {
         jsGetNameEnum = find(library, 'JsGetName');
         jsBuiltinEnum = find(library, 'JsBuiltin');
       } else if (uri == Uris.dart_html) {
         htmlLibraryIsLoaded = true;
       } else if (uri == PACKAGE_LOOKUP_MAP) {
-        lookupMapAnalysis.initRuntimeClass(find(library, 'LookupMap'));
+        lookupMapAnalysis.init(library);
       }
       annotations.onLibraryScanned(library);
     });
   }
 
   Future onLibrariesLoaded(LoadedLibraries loadedLibraries) {
     if (!loadedLibraries.containsLibrary(Uris.dart_core)) {
       return new Future.value();
     }
 
@@ skipping 425 matching lines @@
               new CodegenRegistry(compiler,
                   dependency.annotatedElement.analyzableElement.treeElements),
               addForEmission: false);
         }
         metadataConstants.clear();
       }
     }
     return true;
   }
 
-  void onQueueClosed() => lookupMapAnalysis.onQueueClosed();
+  void onQueueClosed() {
+    lookupMapAnalysis.onQueueClosed();
+  }
+
+  void onCodegenStart() {
+    lookupMapAnalysis.onCodegenStart();
+  }
 
   void onElementResolved(Element element, TreeElements elements) {
     if ((element.isFunction || element.isGenerativeConstructor) &&
         annotations.noInline(element)) {
       inlineCache.markAsNonInlinable(element);
     }
 
     LibraryElement library = element.library;
     if (!library.isPlatformLibrary && !library.canUseNative) return;
     bool hasNoInline = false;
@@ skipping 509 matching lines @@
   }
 }
 
 /// Records that [constant] is used by the element behind [registry].
 class Dependency {
   final ConstantValue constant;
   final Element annotatedElement;
 
   const Dependency(this.constant, this.annotatedElement);
 }