[runtime] Remove the redundant %_IsObject intrinsic.

test/cctest/compiler/test-run-intrinsics.cc

 // Copyright 2014 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.
 
 #include "src/v8.h"
 
 #include "test/cctest/compiler/function-tester.h"
 
 using namespace v8::internal;
 using namespace v8::internal::compiler;
@@ skipping 122 matching lines @@
 
   T.CheckTrue(T.Val(1));
   T.CheckFalse(T.Val(1.1));
   T.CheckFalse(T.Val(-0.0));
   T.CheckFalse(T.Val(-2));
   T.CheckFalse(T.Val(-2.3));
   T.CheckFalse(T.undefined());
 }
 
 
-TEST(IsObject) {
-  FunctionTester T("(function(a) { return %_IsObject(a); })", flags);
-
-  T.CheckFalse(T.NewObject("(function() {})"));
-  T.CheckTrue(T.NewObject("([1])"));
-  T.CheckTrue(T.NewObject("({})"));
-  T.CheckTrue(T.NewObject("(/x/)"));
-  T.CheckFalse(T.undefined());
-  T.CheckTrue(T.null());
-  T.CheckFalse(T.Val("x"));
-  T.CheckFalse(T.Val(1));
-}
-
-
 TEST(IsRegExp) {
   FunctionTester T("(function(a) { return %_IsRegExp(a); })", flags);
 
   T.CheckFalse(T.NewObject("new Date()"));
   T.CheckFalse(T.NewObject("(function() {})"));
   T.CheckFalse(T.NewObject("([1])"));
   T.CheckFalse(T.NewObject("({})"));
   T.CheckTrue(T.NewObject("(/x/)"));
   T.CheckFalse(T.undefined());
   T.CheckFalse(T.null());
@@ skipping 183 matching lines @@
 
 
 TEST(ValueOf) {
   FunctionTester T("(function(a) { return %_ValueOf(a); })", flags);
 
   T.CheckCall(T.Val("a"), T.Val("a"));
   T.CheckCall(T.Val("b"), T.NewObject("(new String('b'))"));
   T.CheckCall(T.Val(123), T.Val(123));
   T.CheckCall(T.Val(456), T.NewObject("(new Number(456))"));
 }