Make toLocaleString on arrays always call toLocaleString on its elements.

test/mjsunit/es6/typedarray-tostring.js

Index: test/mjsunit/es6/typedarray-tostring.js
diff --git a/test/mjsunit/es6/typedarray-tostring.js b/test/mjsunit/es6/typedarray-tostring.js
index e6adda0405764acee981495a8e72deeb3762d604..9d49cb1cc9a76b23c0e638f69bf71c42fa4e6e43 100644
--- a/test/mjsunit/es6/typedarray-tostring.js
+++ b/test/mjsunit/es6/typedarray-tostring.js
@@ -83,4 +83,17 @@ for (var constructor of typedArrayConstructors) {
   assertEquals("1,2", Array.prototype.join.call(a5));
   assertEquals("1,2,3", Array.prototype.toString.call(a5));
   assertEquals("1,2", Array.prototype.toLocaleString.call(a5));
+
+  (function TestToLocaleStringCalls() {
+    let log = [];
+    let pushArgs = (label) => (...args) => log.push(label, args);
+
+    let NumberToLocaleString = Number.prototype.toLocaleString;
+    Number.prototype.toLocaleString = pushArgs("Number");
+
+    (new constructor([1, 2])).toLocaleString();
+    assertEquals(["Number", [], "Number", []], log);
+
+    Number.prototype.toLocaleString = NumberToLocaleString;
+  })();
 }