Split interceptor emitter.

sdk/lib/_internal/compiler/implementation/js_emitter/old_emitter/interceptor_emitter.dart

Index: sdk/lib/_internal/compiler/implementation/js_emitter/old_emitter/interceptor_emitter.dart
diff --git a/sdk/lib/_internal/compiler/implementation/js_emitter/interceptor_emitter.dart b/sdk/lib/_internal/compiler/implementation/js_emitter/old_emitter/interceptor_emitter.dart
similarity index 97%
rename from sdk/lib/_internal/compiler/implementation/js_emitter/interceptor_emitter.dart
rename to sdk/lib/_internal/compiler/implementation/js_emitter/old_emitter/interceptor_emitter.dart
index 603e93b8eb230cca54dd93113bb9649484aab3d9..d2b744cbdb7996852e0425c3391c94f113a3f301 100644
--- a/sdk/lib/_internal/compiler/implementation/js_emitter/interceptor_emitter.dart
+++ b/sdk/lib/_internal/compiler/implementation/js_emitter/old_emitter/interceptor_emitter.dart
@@ -13,19 +13,6 @@ class InterceptorEmitter extends CodeEmitterHelper {
     }
   }
 
-  Set<ClassElement> interceptorsReferencedFromConstants() {
-    Set<ClassElement> classes = new Set<ClassElement>();
-    JavaScriptConstantCompiler handler = backend.constants;
-    List<Constant> constants = handler.getConstantsForEmission();
-    for (Constant constant in constants) {
-      if (constant is InterceptorConstant) {
-        InterceptorConstant interceptorConstant = constant;
-        classes.add(interceptorConstant.dispatchedType.element);
-      }
-    }
-    return classes;
-  }
-
   void emitGetInterceptorMethod(CodeBuffer buffer,
                                 String key,
                                 Set<ClassElement> classes) {