Test that TypedArray methods don't read length

test/mjsunit/harmony/typedarray-fill.js

Index: test/mjsunit/harmony/typedarray-fill.js
diff --git a/test/mjsunit/harmony/typedarray-fill.js b/test/mjsunit/harmony/typedarray-fill.js
index 40605bbd515ea553bcaf9d6c45124020047def1a..4452bf64cdecf7ae3b4da70a2baaa14c18bb12c3 100644
--- a/test/mjsunit/harmony/typedarray-fill.js
+++ b/test/mjsunit/harmony/typedarray-fill.js
@@ -36,4 +36,12 @@ for (var constructor of typedArrayConstructors) {
   assertThrows('constructor.prototype.fill.call(null)', TypeError);
   assertThrows('constructor.prototype.fill.call(undefined)', TypeError);
   assertThrows('constructor.prototype.fill.call([])', TypeError);
+
+  // Shadowing length doesn't affect fill, unlike Array.prototype.fill
+  var a = new constructor([2, 2]);
+  Object.defineProperty(a, 'length', {value: 1});

[arv (Not doing code reviews), 2015/05/15 00:25:47]

or

get: function() { assertUnreachable(); }

[dehrenberg, 2015/05/15 01:40:41]

well, later down I validate the test by making it get reached by
Array.prototype.fill, so not sure if that would really work the way it's
written.

+  a.fill(3);
+  assertArrayEquals([a[0], a[1]], [3, 3]);
+  Array.prototype.fill.call(a, 4);
+  assertArrayEquals([a[0], a[1]], [4, 3]);
 }