Fix issue 1361 - Implement ES5 Array.prototype.toString.

src/array.js

Index: src/array.js
diff --git a/src/array.js b/src/array.js
index 4dd23c8bb464b31b4171e7e671b9a8bb106f1951..7f179ed78b1d23704f342a5a332dfbc49f7e7d22 100644
--- a/src/array.js
+++ b/src/array.js
@@ -381,10 +381,22 @@ function SimpleMove(array, start_i, del_count, len, num_additional_args) {
 
 
 function ArrayToString() {
-  if (!IS_ARRAY(this)) {
-    throw new $TypeError('Array.prototype.toString is not generic');
+  var array;
+  var func;
+  if (IS_ARRAY(this)) {
+    func = this.join;
+    if (func === ArrayJoin) {
+      return Join(this, this.length, ',', ConvertToString);
+    }
+    array = this;
+  } else {
+    array = ToObject(this);
+    func = array.join;
+  }
+  if (!IS_SPEC_FUNCTION(func)) {
+    return %_CallFunction(array, ObjectToString);
   }
-  return Join(this, this.length, ',', ConvertToString);
+  return %_CallFunction(array, func);
 }