[runtime] Remove the redundant %_IsObject intrinsic.

src/x87/lithium-codegen-x87.h

 // Copyright 2012 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_X87_LITHIUM_CODEGEN_X87_H_
 #define V8_X87_LITHIUM_CODEGEN_X87_H_
 
 #include <map>
 #include "src/x87/lithium-x87.h"
 
@@ skipping 280 matching lines @@
   void EmitFalseBranch(InstrType instr, Condition cc);
   void EmitNumberUntagDNoSSE2(LNumberUntagD* instr, Register input,
                               Register temp, X87Register res_reg,
                               NumberUntagDMode mode);
 
   // Emits optimized code for typeof x == "y".  Modifies input register.
   // Returns the condition on which a final split to
   // true and false label should be made, to optimize fallthrough.
   Condition EmitTypeofIs(LTypeofIsAndBranch* instr, Register input);
 
-  // Emits optimized code for %_IsObject(x).  Preserves input register.
-  // Returns the condition on which a final split to
-  // true and false label should be made, to optimize fallthrough.
-  Condition EmitIsObject(Register input,
-                         Register temp1,
-                         Label* is_not_object,
-                         Label* is_object);
-
   // Emits optimized code for %_IsString(x).  Preserves input register.
   // Returns the condition on which a final split to
   // true and false label should be made, to optimize fallthrough.
   Condition EmitIsString(Register input,
                          Register temp1,
                          Label* is_not_string,
                          SmiCheck check_needed);
 
   // Emits optimized code for %_IsConstructCall().
   // Caller should branch on equal condition.
@@ skipping 184 matching lines @@
   Label exit_;
   Label* external_exit_;
   Label done_;
   int instruction_index_;
   LCodeGen::X87Stack x87_stack_;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_X87_LITHIUM_CODEGEN_X87_H_