[runtime] Remove the redundant %_IsObject intrinsic.

src/full-codegen/full-codegen.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_FULL_CODEGEN_FULL_CODEGEN_H_
 #define V8_FULL_CODEGEN_FULL_CODEGEN_H_
 
 #include "src/allocation.h"
 #include "src/assert-scope.h"
 #include "src/ast.h"
@@ skipping 489 matching lines @@
   F(Arguments)                            \
   F(ValueOf)                              \
   F(SetValueOf)                           \
   F(IsDate)                               \
   F(DateField)                            \
   F(StringCharFromCode)                   \
   F(StringCharAt)                         \
   F(OneByteSeqStringSetChar)              \
   F(TwoByteSeqStringSetChar)              \
   F(ObjectEquals)                         \
-  F(IsObject)                             \
   F(IsFunction)                           \
   F(IsSpecObject)                         \
   F(IsSimdValue)                          \
   F(IsStringWrapperSafeForDefaultValueOf) \
   F(MathPow)                              \
   F(IsMinusZero)                          \
   F(HasCachedArrayIndex)                  \
   F(GetCachedArrayIndex)                  \
   F(FastOneByteArrayJoin)                 \
   F(GeneratorNext)                        \
@@ skipping 557 matching lines @@
 
   Address start_;
   Address instruction_start_;
   uint32_t length_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_FULL_CODEGEN_FULL_CODEGEN_H_