Handle array construction in native code (ARM version).

Ported the handle array construction in native code to ARM. See http://codereview.chromium.org/193125 for details. 
Review URL: http://codereview.chromium.org/217014

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2956 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/builtins.cc

@@ -172,7 +172,9 @@ BUILTIN(ArrayCodeGeneric) {
   }
 
   // Optimize the case where there are no parameters passed.
-  if (args.length() == 1) return array->Initialize(4);
+  if (args.length() == 1) {
+    return array->Initialize(JSArray::kPreallocatedArrayElements);
+  }
 
   // Take the arguments as elements.
   int number_of_elements = args.length() - 1;

src/objects.h

@@ -4389,6 +4389,9 @@ class JSArray: public JSObject {
   void JSArrayVerify();
 #endif
 
+  // Number of element slots to pre-allocate for an empty array.
+  static const int kPreallocatedArrayElements = 4;
+
   // Layout description.
   static const int kLengthOffset = JSObject::kHeaderSize;
   static const int kSize = kLengthOffset + kPointerSize;