fix(compiler_cli): normalize used directives

- e.g. needed for content projection.

Closes #8677

modules/@angular/compiler_cli/integrationtest/src/projection.ts

@@ -0,0 +1,15 @@
+import {Component} from '@angular/core';
+
+@Component({
+  selector: 'comp-with-proj',
+  template: '<ng-content></ng-content>'
+})
+export class CompWithProjection {
+}
+
+@Component({
+  selector: 'main',
+  template: '<comp-with-proj><span greeting="Hello world!"></span></comp-with-proj>',
+  directives: [CompWithProjection]
+})
+export class MainComp {}

modules/@angular/compiler_cli/integrationtest/test/projection_spec.ts

@@ -0,0 +1,17 @@
+import {MainCompNgFactory} from '../src/projection.ngfactory';
+import {CompWithProjection} from '../src/projection';
+import {ReflectiveInjector, DebugElement, getDebugNode} from '@angular/core';
+import {browserPlatform, BROWSER_APP_STATIC_PROVIDERS, By} from '@angular/platform-browser';
+
+describe("content projection", () => {
+  it("should support basic content projection", () => {
+    const appInjector = ReflectiveInjector.resolveAndCreate(BROWSER_APP_STATIC_PROVIDERS,
+                                                            browserPlatform().injector);
+    var mainComp = MainCompNgFactory.create(appInjector);
+
+    var debugElement = <DebugElement>getDebugNode(mainComp.location.nativeElement);
+    var compWithProjection = debugElement.query(By.directive(CompWithProjection));
+    expect(compWithProjection.children.length).toBe(1);
+    expect(compWithProjection.children[0].attributes['greeting']).toEqual('Hello world!');
+  });
+});