[es6] Array.prototype.find and findIndex should include holes

test/mjsunit/harmony/array-find.js

Index: test/mjsunit/harmony/array-find.js
diff --git a/test/mjsunit/harmony/array-find.js b/test/mjsunit/harmony/array-find.js
index eb3208227706e6e3654549dac10d47b8197728dd..44fc78292a81123a9535999717c1085159af9874 100644
--- a/test/mjsunit/harmony/array-find.js
+++ b/test/mjsunit/harmony/array-find.js
@@ -201,7 +201,7 @@ assertEquals(22, a.find(function(val) { return 22 === val; }), undefined);
 
 
 //
-// Test predicate is only called for existing elements
+// Test predicate is called for holes
 //
 (function() {
   var a = new Array(30);
@@ -211,7 +211,27 @@ assertEquals(22, a.find(function(val) { return 22 === val; }), undefined);
 
   var count = 0;
   a.find(function() { count++; return false; });
-  assertEquals(3, count);
+  assertEquals(30, count);
+})();
+
+
+(function() {
+  var a = [0, 1, , 3];
+  var count = 0;
+  var found = a.find(function(val) { return val === undefined; });
+  assertEquals(undefined, found);
+})();
+
+
+(function() {
+  var a = [0, 1, , 3];
+  a.__proto__ = {
+    __proto__: Array.prototype,
+    2: 42,
+  };
+  var count = 0;
+  var found = a.find(function(val) { return val === 42; });
+  assertEquals(42, found);
 })();