[runtime] Remove the redundant %_IsObject intrinsic.

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

Index: test/cctest/compiler/test-run-intrinsics.cc
diff --git a/test/cctest/compiler/test-run-intrinsics.cc b/test/cctest/compiler/test-run-intrinsics.cc
index 1fa37748c6753d5e0b64705bc5cb0100088d0d1e..232295965f3d10f181c52b999947172f3567d3a9 100644
--- a/test/cctest/compiler/test-run-intrinsics.cc
+++ b/test/cctest/compiler/test-run-intrinsics.cc
@@ -140,20 +140,6 @@ TEST(IsNonNegativeSmi) {
 }
 
 
-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);