[turbofan] Remove dead code from SimplifiedLowering.

This is follow-up cleanup for the flags that are no longer used inside
SimplifiedLowering.

R=jarin@chromium.org

Review-Url: https://codereview.chromium.org/2132403002
Cr-Commit-Position: refs/heads/master@{#37652}

src/compiler/pipeline.cc

@@ -939,12 +939,8 @@ struct RepresentationSelectionPhase {
   static const char* phase_name() { return "representation selection"; }
 
   void Run(PipelineData* data, Zone* temp_zone) {
-    SimplifiedLowering::Flags flags =
-        data->info()->is_type_feedback_enabled()
-            ? SimplifiedLowering::kTypeFeedbackEnabled
-            : SimplifiedLowering::kNoFlag;
     SimplifiedLowering lowering(data->jsgraph(), temp_zone,
-                                data->source_positions(), flags);
+                                data->source_positions());
     lowering.LowerAllNodes();
   }
 };

src/compiler/simplified-lowering.cc

@@ -2335,12 +2335,10 @@ class RepresentationSelector {
 };
 
 SimplifiedLowering::SimplifiedLowering(JSGraph* jsgraph, Zone* zone,
-                                       SourcePositionTable* source_positions,
-                                       Flags flags)
+                                       SourcePositionTable* source_positions)
     : jsgraph_(jsgraph),
       zone_(zone),
       type_cache_(TypeCache::Get()),
-      flags_(flags),
       source_positions_(source_positions) {}
 
 void SimplifiedLowering::LowerAllNodes() {

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