VM: [Cleanup] Delete legacy code associated with BranchInstr.

runtime/vm/branch_optimizer.cc

 // Copyright (c) 2016, 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/branch_optimizer.h"
 
 #include "vm/flow_graph.h"
 #include "vm/intermediate_language.h"
 
 namespace dart {
@@ skipping 65 matching lines @@
 
 
 BranchInstr* BranchSimplifier::CloneBranch(Zone* zone,
                                            BranchInstr* branch,
                                            Value* new_left,
                                            Value* new_right) {
   ComparisonInstr* comparison = branch->comparison();
   ComparisonInstr* new_comparison =
       comparison->CopyWithNewOperands(new_left, new_right);
   BranchInstr* new_branch = new (zone) BranchInstr(new_comparison);
-  new_branch->set_is_checked(branch->is_checked());
   return new_branch;
 }
 
 
 void BranchSimplifier::Simplify(FlowGraph* flow_graph) {
   // Optimize some branches that test the value of a phi.  When it is safe
   // to do so, push the branch to each of the predecessor blocks.  This is
   // an optimization when (a) it can avoid materializing a boolean object at
   // the phi only to test its value, and (b) it can expose opportunities for
   // constant propagation and unreachable code elimination.  This
@@ skipping 239 matching lines @@
   if (changed) {
     // We may have changed the block order and the dominator tree.
     flow_graph->DiscoverBlocks();
     GrowableArray<BitVector*> dominance_frontier;
     flow_graph->ComputeDominators(&dominance_frontier);
   }
 }
 
 
 }  // namespace dart