Use GPRs for mints

runtime/vm/flow_graph_optimizer.cc

 // Copyright (c) 2013, 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/flow_graph_optimizer.h"
 
 #include "vm/bit_vector.h"
 #include "vm/cha.h"
 #include "vm/cpu.h"
 #include "vm/dart_entry.h"
@@ skipping 584 matching lines @@
     insert_before =
         phi->block()->PredecessorAt(use->use_index())->last_instruction();
     deopt_target = NULL;
   } else {
     deopt_target = insert_before = use->instruction();
   }
 
   Definition* converted = NULL;
   if ((from == kTagged) && (to == kUnboxedMint)) {
     ASSERT((deopt_target != NULL) ||
-           (use->Type()->ToCid() == kDoubleCid));
+           (use->Type()->ToCid() == kUnboxedMint));
     const intptr_t deopt_id = (deopt_target != NULL) ?
         deopt_target->DeoptimizationTarget() : Isolate::kNoDeoptId;
     converted = new UnboxIntegerInstr(use->CopyWithType(), deopt_id);
 
   } else if ((from == kUnboxedMint) && (to == kTagged)) {
     converted = new BoxIntegerInstr(use->CopyWithType());
 
   } else if (from == kUnboxedMint && to == kUnboxedDouble) {
     ASSERT(CanUnboxDouble());
     // Convert by boxing/unboxing.
@@ skipping 9082 matching lines @@
   }
 
   // Insert materializations at environment uses.
   for (intptr_t i = 0; i < exits.length(); i++) {
     CreateMaterializationAt(exits[i], alloc, alloc->cls(), *slots);
   }
 }
 
 
 }  // namespace dart