refactor: remove ts2dart annotations

modules/@angular/core/src/linker/component_factory.ts

@@ -81,7 +81,6 @@ export class ComponentRef_<C> extends ComponentRef<C> {
 
 /**
  * @experimental
- * @ts2dart_const
  */
 const EMPTY_CONTEXT = new Object();
 

modules/@angular/core/src/linker/debug_context.ts

@@ -15,7 +15,6 @@ import {DebugAppView} from './view';
 import {ViewType} from './view_type';
 
 
-/* @ts2dart_const */
 export class StaticNodeDebugInfo {
   constructor(
       public providerTokens: any[], public componentToken: any,

modules/@angular/core/src/linker/element_injector.ts

@@ -9,7 +9,7 @@
 import {Injector, THROW_IF_NOT_FOUND} from '../di/injector';
 import {AppView} from './view';
 
-const _UNDEFINED = /*@ts2dart_const*/ new Object();
+const _UNDEFINED = new Object();
 
 export class ElementInjector extends Injector {
   constructor(private _view: AppView<any>, private _nodeIndex: number) { super(); }

modules/@angular/core/src/linker/template_ref.ts

@@ -12,7 +12,7 @@ import {ElementRef} from './element_ref';
 import {AppView} from './view';
 import {EmbeddedViewRef} from './view_ref';
 
-const EMPTY_CONTEXT = /*@ts2dart_const*/ new Object();
+const EMPTY_CONTEXT = new Object();
 
 /**
  * Represents an Embedded Template that can be used to instantiate Embedded Views.

modules/@angular/core/src/linker/view_utils.ts

@@ -70,7 +70,7 @@ function _flattenNestedViewRenderNodes(nodes: any[], renderNodes: any[]): any[]
   return renderNodes;
 }
 
-const EMPTY_ARR: any[] = /*@ts2dart_const*/[];
+const EMPTY_ARR: any[] = [];
 
 export function ensureSlotCount(projectableNodes: any[][], expectedSlotCount: number): any[][] {
   var res: any[][];