[turbofan] Remove dead code from SimplifiedLowering.

src/compiler/simplified-lowering.h

Index: src/compiler/simplified-lowering.h
diff --git a/src/compiler/simplified-lowering.h b/src/compiler/simplified-lowering.h
index c4ac37a9fce32460121fb15f121bd3188e1dabe5..aebc9bd3cd04418a69c7ab943013e31291831d6f 100644
--- a/src/compiler/simplified-lowering.h
+++ b/src/compiler/simplified-lowering.h
@@ -5,7 +5,6 @@
 #ifndef V8_COMPILER_SIMPLIFIED_LOWERING_H_
 #define V8_COMPILER_SIMPLIFIED_LOWERING_H_
 
-#include "src/base/flags.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/machine-operator.h"
 #include "src/compiler/node.h"
@@ -27,11 +26,8 @@ class SourcePositionTable;
 
 class SimplifiedLowering final {
  public:
-  enum Flag { kNoFlag = 0u, kTypeFeedbackEnabled = 1u << 0 };
-  typedef base::Flags<Flag> Flags;
   SimplifiedLowering(JSGraph* jsgraph, Zone* zone,
-                     SourcePositionTable* source_positions,
-                     Flags flags = kNoFlag);
+                     SourcePositionTable* source_positions);
   ~SimplifiedLowering() {}
 
   void LowerAllNodes();
@@ -47,15 +43,12 @@ class SimplifiedLowering final {
   void DoStoreBuffer(Node* node);
   void DoShift(Node* node, Operator const* op, Type* rhs_type);
 
-  Flags flags() const { return flags_; }
-
  private:
   JSGraph* const jsgraph_;
   Zone* const zone_;
   TypeCache const& type_cache_;
   SetOncePointer<Node> to_number_code_;
   SetOncePointer<Operator const> to_number_operator_;
-  Flags flags_;
 
   // TODO(danno): SimplifiedLowering shouldn't know anything about the source
   // positions table, but must for now since there currently is no other way to