Vector ICs: Introduce an InstanceType for the type feedback vector.

test/mjsunit/call-counts.js

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Flags: --allow-natives-syntax --noalways-opt
 
 // Locations in the type feedback vector where call counts are maintained for
 // the two calls made from bar();
 const kFooCallExtraIndex = 5;
 const kArrayCallExtraIndex = 9;
 
 function GetCallCount(func, slot) {
   var vector = %GetTypeFeedbackVector(func);
   // Call counts are recorded doubled.
-  var value = %FixedArrayGet(vector, slot);
+  var value = %FeedbackVectorGet(vector, slot);
   return Math.floor(value / 2);
 }
 
 function foo(a) { return a[3] * 16; }
 
 function bar(a) {
   var result = 0;
   for (var i = 0; i < 10; i++) {
     result = foo(a);
     if (i % 2 === 0) {
       var r = Array();
       r[0] = 1;
       result += r[0];
     }
   }
   return result;
 }
 
 var a = [1, 2, 3];
 bar(a);
 assertEquals(10, GetCallCount(bar, kFooCallExtraIndex));
 assertEquals(5, GetCallCount(bar, kArrayCallExtraIndex));
 
 %OptimizeFunctionOnNextCall(bar);
 bar(a);