Intrinsify [] for ExternalUint8 and Uint8 typed data.

tests/standalone/typed_data_test.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 //
 // Dart test program for testing typed data.
 
 // VMOptions=--optimization_counter_threshold=10
 
 // Library tag to be able to run in html test framework.
 library TypedDataTest;
@@ skipping 42 matching lines @@
   typed_data[3] = 127;
   Expect.equals(127, typed_data[3]);
   // This should eventually throw.
   typed_data[0] = 128;
   typed_data[4] = -129;
   if (check_throws) {
     Expect.throws(() {
       typed_data[1] = 1.2;
     });
   }
+  Expect.throws(() => typed_data[-1]);
+  Expect.throws(() => typed_data[100]);
+  Expect.throws(() => typed_data[2.0]);
 }
 
 void testUnsignedTypedDataRange(bool check_throws) {
   Uint8List typed_data;
   typed_data = new Uint8List(10);
 
   typed_data[1] = 255;
   Expect.equals(255, typed_data[1]);
   typed_data[1] = 0;
   Expect.equals(0, typed_data[1]);
 
   for (int i = 0; i < typed_data.length; i++) {
     typed_data[i] = i;
   }
   for (int i = 0; i < typed_data.length; i++) {
     Expect.equals(i, typed_data[i]);
   }
 
   // These should eventually throw.
   typed_data[1] = 256;
   typed_data[1] = -1;
   typed_data[2] = -129;
   if (check_throws) {
     Expect.throws(() {
       typed_data[1] = 1.2;
     });
   }
+  Expect.throws(() => typed_data[-1]);
+  Expect.throws(() => typed_data[100]);
+  Expect.throws(() => typed_data[2.0]);
 }
 
 void testClampedUnsignedTypedDataRangeHelper(Uint8ClampedList typed_data,
                                              bool check_throws) {
   Uint8ClampedList typed_data;
   typed_data = new Uint8ClampedList(10);
 
   typed_data[1] = 255;
   Expect.equals(255, typed_data[1]);
   typed_data[1] = 0;
@@ skipping 305 matching lines @@
     testSetAtIndex(float64list, 1.4260258159703532e-105, true);
     testGetAtIndex(float64list, 1.4260258159703532e-105);
   }
   testTypedDataRange(true);
   testUnsignedTypedDataRange(true);
   testViewCreation();
   testWhere();
   testCreationFromList();
 }