[turbofan] Remove dead {is_liveness_analysis_enabled}.

src/compiler/bytecode-graph-builder.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_BYTECODE_GRAPH_BUILDER_H_
 #define V8_COMPILER_BYTECODE_GRAPH_BUILDER_H_
 
 #include "src/compiler/bytecode-analysis.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/liveness-analyzer.h"
@@ skipping 243 matching lines @@
   }
 
   const BytecodeAnalysis* bytecode_analysis() const {
     return bytecode_analysis_;
   }
 
   void set_bytecode_analysis(const BytecodeAnalysis* bytecode_analysis) {
     bytecode_analysis_ = bytecode_analysis;
   }
 
-  bool IsLivenessAnalysisEnabled() const {
-    return this->is_liveness_analysis_enabled_;
-  }
-
 #define DECLARE_VISIT_BYTECODE(name, ...) void Visit##name();
   BYTECODE_LIST(DECLARE_VISIT_BYTECODE)
 #undef DECLARE_VISIT_BYTECODE
 
   Zone* local_zone_;
   JSGraph* jsgraph_;
   float const invocation_frequency_;
   Handle<BytecodeArray> bytecode_array_;
   Handle<HandlerTable> exception_handler_table_;
   Handle<TypeFeedbackVector> feedback_vector_;
@@ skipping 18 matching lines @@
   Node** input_buffer_;
 
   // Nodes representing values in the activation record.
   SetOncePointer<Node> function_context_;
   SetOncePointer<Node> function_closure_;
   SetOncePointer<Node> new_target_;
 
   // Control nodes that exit the function body.
   ZoneVector<Node*> exit_controls_;
 
-  bool const is_liveness_analysis_enabled_;
-
   StateValuesCache state_values_cache_;
 
   // The source position table, to be populated.
   SourcePositionTable* source_positions_;
 
   SourcePosition const start_position_;
 
   static int const kBinaryOperationHintIndex = 1;
   static int const kCountOperationHintIndex = 0;
   static int const kBinaryOperationSmiHintIndex = 2;
 
   DISALLOW_COPY_AND_ASSIGN(BytecodeGraphBuilder);
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_BYTECODE_GRAPH_BUILDER_H_