[turbofan] Improve some heuristics in escape analysis

src/compiler/escape-analysis.h

Index: src/compiler/escape-analysis.h
diff --git a/src/compiler/escape-analysis.h b/src/compiler/escape-analysis.h
index bba5d98543f94b8545fe9d68fb33fed4c7b09d6e..cfe2f521aa4472c8b0134290c0d2ba03f1c8c4d2 100644
--- a/src/compiler/escape-analysis.h
+++ b/src/compiler/escape-analysis.h
@@ -73,7 +73,6 @@ class EscapeStatusAnalysis {
   static const Alias kUntrackable;
 
   bool IsNotReachable(Node* node);
-  ZoneVector<Node*>& stack() { return stack_; }
 
  private:
   void Process(Node* node);
@@ -170,7 +169,6 @@ class EscapeAnalysis {
   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);
   }