[stubs] remove unused BranchIfSameValueZero from CodeStubAssembler

src/code-stub-assembler.h

 // Copyright 2016 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_CODE_STUB_ASSEMBLER_H_
 #define V8_CODE_STUB_ASSEMBLER_H_
 
 #include <functional>
 
 #include "src/compiler/code-assembler.h"
@@ skipping 153 matching lines @@
 
   void BranchIfSimd128Equal(compiler::Node* lhs, compiler::Node* lhs_map,
                             compiler::Node* rhs, compiler::Node* rhs_map,
                             Label* if_equal, Label* if_notequal);
   void BranchIfSimd128Equal(compiler::Node* lhs, compiler::Node* rhs,
                             Label* if_equal, Label* if_notequal) {
     BranchIfSimd128Equal(lhs, LoadMap(lhs), rhs, LoadMap(rhs), if_equal,
                          if_notequal);
   }
 
-  void BranchIfSameValueZero(compiler::Node* a, compiler::Node* b,
-                             compiler::Node* context, Label* if_true,
-                             Label* if_false);
-
   void BranchIfFastJSArray(compiler::Node* object, compiler::Node* context,
                            Label* if_true, Label* if_false);
 
   // Load value from current frame by given offset in bytes.
   compiler::Node* LoadFromFrame(int offset,
                                 MachineType rep = MachineType::AnyTagged());
   // Load value from current parent frame by given offset in bytes.
   compiler::Node* LoadFromParentFrame(
       int offset, MachineType rep = MachineType::AnyTagged());
 
@@ skipping 641 matching lines @@
                                            Label* bailout);
 
   static const int kElementLoopUnrollThreshold = 8;
 };
 
 DEFINE_OPERATORS_FOR_FLAGS(CodeStubAssembler::AllocationFlags);
 
 }  // namespace internal
 }  // namespace v8
 #endif  // V8_CODE_STUB_ASSEMBLER_H_