[turbofan] Clean up and factor out branch generation logic.

src/compiler/arm/instruction-selector-arm.cc

 // Copyright 2014 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.
 
 #include "src/base/bits.h"
 #include "src/compiler/instruction-selector-impl.h"
 #include "src/compiler/node-matchers.h"
 
 namespace v8 {
 namespace internal {
@@ skipping 1152 matching lines @@
                    value_operand);
   }
 }
 
 }  // namespace
 
 
 void InstructionSelector::VisitBranch(Node* branch, BasicBlock* tbranch,
                                       BasicBlock* fbranch) {
   FlagsContinuation cont(kNotEqual, tbranch, fbranch);
-  if (IsNextInAssemblyOrder(tbranch)) {  // We can fallthru to the true block.
-    cont.Negate();
-    cont.SwapBlocks();
-  }
   VisitWordCompareZero(this, branch, branch->InputAt(0), &cont);
 }
 
 
 void InstructionSelector::VisitWord32Equal(Node* const node) {
   FlagsContinuation cont(kEqual, node);
   Int32BinopMatcher m(node);
   if (m.right().Is(0)) {
     return VisitWordCompareZero(this, m.node(), m.left().node(), &cont);
   }
@@ skipping 75 matching lines @@
              MachineOperatorBuilder::kFloat64Ceil |
              MachineOperatorBuilder::kFloat64RoundTruncate |
              MachineOperatorBuilder::kFloat64RoundTiesAway;
   }
   return flags;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8