[turbofan] Add support for accessing Uint8ClampedArrays.

test/mjsunit/compiler/uint8-clamped-array.js

Index: test/mjsunit/compiler/uint8-clamped-array.js
diff --git a/test/mjsunit/compiler/uint8-clamped-array.js b/test/mjsunit/compiler/uint8-clamped-array.js
new file mode 100644
index 0000000000000000000000000000000000000000..66274d54d14a31a49d99bd3d86bfba8ec071fca3
--- /dev/null
+++ b/test/mjsunit/compiler/uint8-clamped-array.js
@@ -0,0 +1,73 @@
+// Copyright 2016 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --allow-natives-syntax
+
+(function() {
+  function foo(a, v) {
+    a[0] = v & 0xff;
+  }
+
+  var a = new Uint8ClampedArray(4);
+  foo(a, 1);
+  foo(a, 2);
+  %OptimizeFunctionOnNextCall(foo);
+  foo(a, 256);
+  assertOptimized(foo);
+  assertEquals(0, a[0]);
+})();
+
+(function() {
+  function foo(a, v) {
+    a[0] = v >>> 0;
+  }
+
+  var a = new Uint8ClampedArray(4);
+  foo(a, 1);
+  foo(a, 2);
+  %OptimizeFunctionOnNextCall(foo);
+  foo(a, 256);
+  assertOptimized(foo);
+  assertEquals(255, a[0]);
+})();
+
+(function() {
+  function foo(a, v) {
+    a[0] = v | 0;
+  }
+
+  var a = new Uint8ClampedArray(4);
+  foo(a, 1);
+  foo(a, 2);
+  %OptimizeFunctionOnNextCall(foo);
+  foo(a, 256);
+  assertOptimized(foo);
+  assertEquals(255, a[0]);
+  foo(a, -1);
+  assertOptimized(foo);
+  assertEquals(0, a[0]);
+})();
+
+(function() {
+  function foo(a, v) {
+    a[0] = v;
+  }
+
+  var a = new Uint8ClampedArray(4);
+  foo(a, 1);
+  foo(a, 2);
+  %OptimizeFunctionOnNextCall(foo);
+  foo(a, Infinity);
+  assertOptimized(foo);
+  assertEquals(255, a[0]);
+  foo(a, -Infinity);
+  assertOptimized(foo);
+  assertEquals(0, a[0]);
+  foo(a, 0.5);
+  assertOptimized(foo);
+  assertEquals(0, a[0]);
+  foo(a, 1.5);
+  assertOptimized(foo);
+  assertEquals(2, a[0]);
+})();