Test that TypedArray methods don't read length

test/mjsunit/harmony/typedarray-findindex.js

 // Copyright 2014 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: --harmony-arrays
 
 var typedArrayConstructors = [
   Uint8Array,
   Int8Array,
   Uint16Array,
@@ skipping 158 matching lines @@
 assertThrows('new constructor([]).findIndex(null)', TypeError);
 assertThrows('new constructor([]).findIndex(undefined)', TypeError);
 assertThrows('new constructor([]).findIndex(0)', TypeError);
 assertThrows('new constructor([]).findIndex(true)', TypeError);
 assertThrows('new constructor([]).findIndex(false)', TypeError);
 assertThrows('new constructor([]).findIndex("")', TypeError);
 assertThrows('new constructor([]).findIndex({})', TypeError);
 assertThrows('new constructor([]).findIndex([])', TypeError);
 assertThrows('new constructor([]).findIndex(/\d+/)', TypeError);
 
+// Shadowing length doesn't affect findIndex, unlike Array.prototype.findIndex
+a = new constructor([1, 2]);
+Object.defineProperty(a, 'length', {value: 1});
+var x = 0;
+assertEquals(a.findIndex(function(elt) { x += elt; return false; }), -1);
+assertEquals(x, 3);
+assertEquals(Array.prototype.findIndex.call(a,
+    function(elt) { x += elt; return false; }), -1);
+assertEquals(x, 4);
+
 }