feat(core): Moving Renderer3 into @angular/core (#20855)

PR Close #20855

packages/core/src/render3/util.ts

@@ -0,0 +1,23 @@
+/**
+ * @license
+ * Copyright Google Inc. All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+/**
+* Must use this method for CD (instead of === ) since NaN !== NaN
+*/
+export function isDifferent(a: any, b: any): boolean {
+  // NaN is the only value that is not equal to itself so the first
+  // test checks if both a and b are not NaN
+  return !(a !== a && b !== b) && a !== b;
+}
+
+export function stringify(value: any): string {
+  if (typeof value == 'function') return value.name || value;
+  if (typeof value == 'string') return value;
+  if (value == null) return '';
+  return '' + value;
+}