[runtime] Simplify TO_INT32/TO_UINT32 abstract operations.

src/array.js

Index: src/array.js
diff --git a/src/array.js b/src/array.js
index 7d0fdcafb3d3ef86a9a03c91baef02778553dbe0..cfaa324d18b506fb24ceff19e5f5239fda34c8d4 100644
--- a/src/array.js
+++ b/src/array.js
@@ -1232,7 +1232,7 @@ function ArrayFilter(f, receiver) {
   // Pull out the length so that modifications to the length in the
   // loop will not affect the looping and side effects are visible.
   var array = TO_OBJECT(this);
-  var length = $toUint32(array.length);
+  var length = TO_UINT32(array.length);
   var accumulator = InnerArrayFilter(f, receiver, array, length);
   var result = new GlobalArray();
   %MoveArrayContents(accumulator, result);
@@ -1543,7 +1543,7 @@ function ArrayReduce(callback, current) {
   // Pull out the length so that modifications to the length in the
   // loop will not affect the looping and side effects are visible.
   var array = TO_OBJECT(this);
-  var length = $toUint32(array.length);
+  var length = TO_UINT32(array.length);
   return InnerArrayReduce(callback, current, array, length,
                           %_ArgumentsLength());
 }
@@ -1586,7 +1586,7 @@ function ArrayReduceRight(callback, current) {
   // Pull out the length so that side effects are visible before the
   // callback function is checked.
   var array = TO_OBJECT(this);
-  var length = $toUint32(array.length);
+  var length = TO_UINT32(array.length);
   return InnerArrayReduceRight(callback, current, array, length,
                                %_ArgumentsLength());
 }