[turbofan] Single entry into deferred regions

src/compiler/register-allocator-verifier.h

 // 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.
 
 #ifndef V8_REGISTER_ALLOCATOR_VERIFIER_H_
 #define V8_REGISTER_ALLOCATOR_VERIFIER_H_
 
 #include "src/zone-containers.h"
 
 namespace v8 {
@@ skipping 56 matching lines @@
 // will determine if the way the operand is defined (from the predecessors)
 // matches a particular use. This handles scenarios where multiple phis are
 // defined with identical operands, and the move optimizer moved down the moves
 // separating the 2 phis in the block defining them.
 class PendingAssessment final : public Assessment {
  public:
   explicit PendingAssessment(const InstructionBlock* origin,
                              InstructionOperand operand)
       : Assessment(Pending), origin_(origin), operand_(operand) {}
 
-  static PendingAssessment* cast(Assessment* assessment) {
+  static const PendingAssessment* cast(const Assessment* assessment) {
     CHECK(assessment->kind() == Pending);
-    return static_cast<PendingAssessment*>(assessment);
+    return static_cast<const PendingAssessment*>(assessment);
   }
 
   const InstructionBlock* origin() const { return origin_; }
   InstructionOperand operand() const { return operand_; }
 
  private:
   const InstructionBlock* const origin_;
   InstructionOperand operand_;
 
   DISALLOW_COPY_AND_ASSIGN(PendingAssessment);
@@ skipping 167 matching lines @@
   ZoneMap<RpoNumber, DelayedAssessments*> outstanding_assessments_;
 
   DISALLOW_COPY_AND_ASSIGN(RegisterAllocatorVerifier);
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif