[runtime] Remove the redundant %_IsObject intrinsic.

src/x64/lithium-x64.h

Index: src/x64/lithium-x64.h
diff --git a/src/x64/lithium-x64.h b/src/x64/lithium-x64.h
index 3e63d10c244fa1ff4df617aa904f4da415021790..e66acc0b647c93562a56a9264f287419bdffc199 100644
--- a/src/x64/lithium-x64.h
+++ b/src/x64/lithium-x64.h
@@ -91,7 +91,6 @@ class LCodeGen;
   V(Integer32ToDouble)                       \
   V(InvokeFunction)                          \
   V(IsConstructCallAndBranch)                \
-  V(IsObjectAndBranch)                       \
   V(IsStringAndBranch)                       \
   V(IsSmiAndBranch)                          \
   V(IsUndetectableAndBranch)                 \
@@ -983,21 +982,6 @@ class LCompareMinusZeroAndBranch final : public LControlInstruction<1, 0> {
 };
 
 
-class LIsObjectAndBranch final : public LControlInstruction<1, 0> {
- public:
-  explicit LIsObjectAndBranch(LOperand* value) {
-    inputs_[0] = value;
-  }
-
-  LOperand* value() { return inputs_[0]; }
-
-  DECLARE_CONCRETE_INSTRUCTION(IsObjectAndBranch, "is-object-and-branch")
-  DECLARE_HYDROGEN_ACCESSOR(IsObjectAndBranch)
-
-  void PrintDataTo(StringStream* stream) override;
-};
-
-
 class LIsStringAndBranch final : public LControlInstruction<1, 1> {
  public:
   explicit LIsStringAndBranch(LOperand* value, LOperand* temp) {