[turbofan] Improve some heuristics in escape analysis

src/compiler/escape-analysis.h

 // Copyright 2015 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_COMPILER_ESCAPE_ANALYSIS_H_
 #define V8_COMPILER_ESCAPE_ANALYSIS_H_
 
 #include "src/base/flags.h"
 #include "src/compiler/graph.h"
 
@@ skipping 55 matching lines @@
   Graph* graph() const { return graph_; }
   Zone* zone() const { return zone_; }
   void AssignAliases();
   Alias GetAlias(NodeId id) const { return aliases_[id]; }
   const ZoneVector<Alias>& GetAliasMap() const { return aliases_; }
   Alias AliasCount() const { return next_free_alias_; }
   static const Alias kNotReachable;
   static const Alias kUntrackable;
 
   bool IsNotReachable(Node* node);
-  ZoneVector<Node*>& stack() { return stack_; }
 
  private:
   void Process(Node* node);
   void ProcessAllocate(Node* node);
   void ProcessFinishRegion(Node* node);
   void ProcessStoreField(Node* node);
   void ProcessStoreElement(Node* node);
   bool CheckUsesForEscape(Node* node, bool phi_escaping = false) {
     return CheckUsesForEscape(node, node, phi_escaping);
   }
@@ skipping 76 matching lines @@
 
   VirtualObject* GetVirtualObject(VirtualState* state, Node* node);
 
   void DebugPrint();
   void DebugPrintState(VirtualState* state);
   void DebugPrintObject(VirtualObject* state, Alias id);
 
   Graph* graph() const { return status_analysis_.graph(); }
   Zone* zone() const { return status_analysis_.zone(); }
   CommonOperatorBuilder* common() const { return common_; }
-  ZoneVector<Node*>& stack() { return status_analysis_.stack(); }
   bool IsEffectBranchPoint(Node* node) {
     return status_analysis_.IsEffectBranchPoint(node);
   }
   bool IsDanglingEffectNode(Node* node) {
     return status_analysis_.IsDanglingEffectNode(node);
   }
   bool IsNotReachable(Node* node) {
     return status_analysis_.IsNotReachable(node);
   }
   Alias GetAlias(NodeId id) const { return status_analysis_.GetAlias(id); }
   Alias AliasCount() const { return status_analysis_.AliasCount(); }
 
   EscapeStatusAnalysis status_analysis_;
   CommonOperatorBuilder* const common_;
   ZoneVector<VirtualState*> virtual_states_;
   ZoneVector<Node*> replacements_;
   MergeCache* cache_;
 
   DISALLOW_COPY_AND_ASSIGN(EscapeAnalysis);
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_ESCAPE_ANALYSIS_H_