[turbofan] Tune the ValueNumberingReducer's growth rate

src/compiler/value-numbering-reducer.h

Index: src/compiler/value-numbering-reducer.h
diff --git a/src/compiler/value-numbering-reducer.h b/src/compiler/value-numbering-reducer.h
index 724c6bd58873a940c3b5a1095861475ee764b348..f52e13b45c98a044c13fa4d80bed2f65b20dd53b 100644
--- a/src/compiler/value-numbering-reducer.h
+++ b/src/compiler/value-numbering-reducer.h
@@ -22,7 +22,7 @@ class V8_EXPORT_PRIVATE ValueNumberingReducer final
   Reduction Reduce(Node* node) override;
 
  private:
-  enum { kInitialCapacity = 256u, kCapacityToSizeRatio = 2u };
+  enum { kInitialCapacity = 256u };
 
   void Grow();
   Zone* temp_zone() const { return temp_zone_; }