refactor(compiler): set element attributes via one call

This makes the cost of using directives that have host attributes
smaller.

Part of #11683

modules/@angular/compiler/src/compiler_util/identifier_util.ts

@@ -0,0 +1,36 @@
+/**
+ * @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
+ */
+
+import {CompileTokenMetadata} from '../compile_metadata';
+import {isPresent} from '../facade/lang';
+import {Identifiers, resolveIdentifier} from '../identifiers';
+import * as o from '../output/output_ast';
+
+export function createDiTokenExpression(token: CompileTokenMetadata): o.Expression {
+  if (isPresent(token.value)) {
+    return o.literal(token.value);
+  } else if (token.identifierIsInstance) {
+    return o.importExpr(token.identifier)
+        .instantiate([], o.importType(token.identifier, [], [o.TypeModifier.Const]));
+  } else {
+    return o.importExpr(token.identifier);
+  }
+}
+
+export function createFastArray(values: o.Expression[]): o.Expression {
+  if (values.length === 0) {
+    return o.importExpr(resolveIdentifier(Identifiers.EMPTY_FAST_ARRAY));
+  }
+  const index = Math.ceil(values.length / 2) - 1;
+  const identifierSpec = index < Identifiers.fastArrays.length ? Identifiers.fastArrays[index] :
+                                                                 Identifiers.FastArrayDynamic;
+  const identifier = resolveIdentifier(identifierSpec);
+  return o.importExpr(identifier).instantiate([
+    <o.Expression>o.literal(values.length)
+  ].concat(values));
+}