Ensure global view registry is aliased when view registry is used.

In Ember 1.12.0 and 1.12.1 the `-view-registry:main` was introduced as a
mechanism to track views without mutating the global `Ember.View.views`
registry (needed for fastboot work), unfortunately the
`Ember.EventDispatcher` was not updated to use the new view registry and
therefore any views added in a view registry other than
`Ember.View.views` will not be able to handle DOM events.

This change ensures that `-view-registry:main` is the same as
`Ember.View.views` on Ember versions where `Ember.View.views` exists
(Ember < 1.13.0).

lib/ember-test-helpers/test-module-for-component.js

@@ -42,6 +42,21 @@ export default TestModule.extend({
       this.setupSteps.push(this.setupComponentIntegrationTest);
       this.teardownSteps.push(this.teardownComponent);
     }
+
+    if (Ember.View && Ember.View.views) {
+      this.setupSteps.push(this._aliasViewRegistry);
+      this.teardownSteps.push(this._resetViewRegistry);
+    }
+  },
+
+  _aliasViewRegistry: function() {
+    this._originalGlobalViewRegistry = Ember.View.views;
+    var viewRegistry = this.container.lookup('-view-registry:main');
+    Ember.View.views = viewRegistry;
+  },
+
+  _resetViewRegistry: function() {
+    Ember.View.views = this._originalGlobalViewRegistry;
   },
 
   setupComponentUnitTest: function() {

lib/ember-test-helpers/test-module.js

@@ -184,7 +184,7 @@ export default Klass.extend({
 
     // Ember 2.0.0 removed Ember.View as public API, so only do this when
     // Ember.View is present
-    if (Ember.View) {
+    if (Ember.View && Ember.View.views) {
       Ember.View.views = {};
     }
   },