Re-apply r20377.

runtime/vm/bit_vector.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/bit_vector.h"
 
 #include "vm/os.h"
 
 namespace dart {
 
@@ skipping 70 matching lines @@
   for (intptr_t i = 0; i < data_length_; i++) {
     const uword before = data_[i];
     const uword after = data_[i] | (gen->data_[i] & ~kill->data_[i]);
     if (before != after) changed = true;
     data_[i] = after;
   }
   return changed;
 }
 
 
-void BitVector::Intersect(const BitVector& other) {
-  ASSERT(other.length() == length());
+void BitVector::Intersect(const BitVector* other) {
+  ASSERT(other->length() == length());
   for (int i = 0; i < data_length_; i++) {
-    data_[i] = data_[i] & other.data_[i];
+    data_[i] = data_[i] & other->data_[i];
   }
 }
 
 
 void BitVector::Print() const {
   OS::Print("[");
   for (intptr_t i = 0; i < length_; i++) {
     OS::Print(Contains(i) ? "1" : "0");
   }
   OS::Print("]");
 }
 
 }  // namespace dart