Use intrinsics for builtin ArrayBuffer property accesses

src/arraybuffer.js

Index: src/arraybuffer.js
diff --git a/src/arraybuffer.js b/src/arraybuffer.js
index 6125f0f61cb3eb1a258573106a5f4bb2daa7ee17..cfaa8d7efca4689b9b715cd3fb34212d6e35346e 100644
--- a/src/arraybuffer.js
+++ b/src/arraybuffer.js
@@ -57,17 +57,18 @@ function ArrayBufferSlice(start, end) {
 
   var relativeStart = TO_INTEGER(start);
   var first;
+  var byte_length = %ArrayBufferGetByteLength(this);
   if (relativeStart < 0) {
-    first = MathMax(this.byteLength + relativeStart, 0);
+    first = MathMax(byte_length + relativeStart, 0);
   } else {
-    first = MathMin(relativeStart, this.byteLength);
+    first = MathMin(relativeStart, byte_length);
   }
-  var relativeEnd = IS_UNDEFINED(end) ? this.byteLength : TO_INTEGER(end);
+  var relativeEnd = IS_UNDEFINED(end) ? byte_length : TO_INTEGER(end);
   var fin;
   if (relativeEnd < 0) {
-    fin = MathMax(this.byteLength + relativeEnd, 0);
+    fin = MathMax(byte_length + relativeEnd, 0);
   } else {
-    fin = MathMin(relativeEnd, this.byteLength);
+    fin = MathMin(relativeEnd, byte_length);
   }
 
   if (fin < first) {