Don't generate forwarding hooks if all noSuchMethod implementations

pkg/compiler/lib/src/compiler.dart

Index: pkg/compiler/lib/src/compiler.dart
diff --git a/pkg/compiler/lib/src/compiler.dart b/pkg/compiler/lib/src/compiler.dart
index bd636e43a98c5c2f623e183ea38a58fa566a4e1a..ea8c60cb0b32beb85f61226f7cd163eb7bab370c 100644
--- a/pkg/compiler/lib/src/compiler.dart
+++ b/pkg/compiler/lib/src/compiler.dart
@@ -361,13 +361,14 @@ abstract class Backend {
    */
   void registerRuntimeType(Enqueuer enqueuer, Registry registry) {}
 
-  /**
-   * Call this method to enable [noSuchMethod] handling in the
-   * backend.
-   */
-  void enableNoSuchMethod(Element context, Enqueuer enqueuer) {
-    enqueuer.registerInvocation(compiler.noSuchMethodSelector);
-  }
+  /// Call this to register a `noSuchMethod` implementation.
+  void registerNoSuchMethod(Element noSuchMethodElement) {}
+
+  /// Call this method to enable support for `noSuchMethod`.
+  void enableNoSuchMethod(Enqueuer enqueuer) {}
+
+  /// Returns whether or not `noSuchMethod` support has been enabled.
+  bool get enabledNoSuchMethod => false;
 
   /// Call this method to enable support for isolates.
   void enableIsolateSupport(Enqueuer enqueuer) {}
@@ -949,7 +950,6 @@ abstract class Compiler implements DiagnosticListener {
   final Selector symbolValidatedConstructorSelector = new Selector.call(
       'validated', null, 1);
 
-  bool enabledNoSuchMethod = false;
   bool enabledRuntimeType = false;
   bool enabledFunctionApply = false;
   bool enabledInvokeOn = false;
@@ -1623,9 +1623,6 @@ abstract class Compiler implements DiagnosticListener {
     if (hasIsolateSupport) {
       backend.enableIsolateSupport(enqueuer.codegen);
     }
-    if (enabledNoSuchMethod) {
-      backend.enableNoSuchMethod(null, enqueuer.codegen);
-    }
     if (compileAll) {
       libraryLoader.libraries.forEach((LibraryElement library) {
         fullyEnqueueLibrary(library, enqueuer.codegen);