Merge up to 8597 to experimental/gc from the bleeding edge.

src/array.js

Index: src/array.js
===================================================================
--- src/array.js	(revision 8618)
+++ src/array.js	(working copy)
@@ -631,7 +631,9 @@
 
   if (end_i < start_i) return result;
 
-  if (IS_ARRAY(this)) {
+  if (IS_ARRAY(this) &&
+      (end_i > 1000) &&
+      (%EstimateNumberOfElements(this) < end_i)) {
     SmartSlice(this, start_i, end_i - start_i, len, result);
   } else {
     SimpleSlice(this, start_i, end_i - start_i, len, result);
@@ -740,14 +742,15 @@
       else return x < y ? -1 : 1;
     };
   }
-  var global_receiver = %GetGlobalReceiver();
+  var receiver =
+      %_IsNativeOrStrictMode(comparefn) ? void 0 : %GetGlobalReceiver();
 
   function InsertionSort(a, from, to) {
     for (var i = from + 1; i < to; i++) {
       var element = a[i];
       for (var j = i - 1; j >= from; j--) {
         var tmp = a[j];
-        var order = %_CallFunction(global_receiver, tmp, element, comparefn);
+        var order = %_CallFunction(receiver, tmp, element, comparefn);
         if (order > 0) {
           a[j + 1] = tmp;
         } else {
@@ -769,14 +772,14 @@
     var v1 = a[to - 1];
     var middle_index = from + ((to - from) >> 1);
     var v2 = a[middle_index];
-    var c01 = %_CallFunction(global_receiver, v0, v1, comparefn);
+    var c01 = %_CallFunction(receiver, v0, v1, comparefn);
     if (c01 > 0) {
       // v1 < v0, so swap them.
       var tmp = v0;
       v0 = v1;
       v1 = tmp;
     } // v0 <= v1.
-    var c02 = %_CallFunction(global_receiver, v0, v2, comparefn);
+    var c02 = %_CallFunction(receiver, v0, v2, comparefn);
     if (c02 >= 0) {
       // v2 <= v0 <= v1.
       var tmp = v0;
@@ -785,7 +788,7 @@
       v1 = tmp;
     } else {
       // v0 <= v1 && v0 < v2
-      var c12 = %_CallFunction(global_receiver, v1, v2, comparefn);
+      var c12 = %_CallFunction(receiver, v1, v2, comparefn);
       if (c12 > 0) {
         // v0 <= v2 < v1
         var tmp = v1;
@@ -806,7 +809,7 @@
     // From i to high_start are elements that haven't been compared yet.
     partition: for (var i = low_end + 1; i < high_start; i++) {
       var element = a[i];
-      var order = %_CallFunction(global_receiver, element, pivot, comparefn);
+      var order = %_CallFunction(receiver, element, pivot, comparefn);
       if (order < 0) {
         %_SwapElements(a, i, low_end);
         low_end++;
@@ -815,7 +818,7 @@
           high_start--;
           if (high_start == i) break partition;
           var top_elem = a[high_start];
-          order = %_CallFunction(global_receiver, top_elem, pivot, comparefn);
+          order = %_CallFunction(receiver, top_elem, pivot, comparefn);
         } while (order > 0);
         %_SwapElements(a, i, high_start);
         if (order < 0) {
@@ -1250,7 +1253,7 @@
   for (; i < length; i++) {
     var element = this[i];
     if (!IS_UNDEFINED(element) || i in this) {
-      current = callback.call(null, current, element, i, this);
+      current = callback.call(void 0, current, element, i, this);
     }
   }
   return current;
@@ -1281,7 +1284,7 @@
   for (; i >= 0; i--) {
     var element = this[i];
     if (!IS_UNDEFINED(element) || i in this) {
-      current = callback.call(null, current, element, i, this);
+      current = callback.call(void 0, current, element, i, this);
     }
   }
   return current;