[runtime] Remove the redundant %_IsObject intrinsic.

src/mips/lithium-mips.h

Index: src/mips/lithium-mips.h
diff --git a/src/mips/lithium-mips.h b/src/mips/lithium-mips.h
index 66bfe8b7ac678063698c692ec0227fee7c908631..93dd2c898d1adb33f9defdf0b507bf652ad49764 100644
--- a/src/mips/lithium-mips.h
+++ b/src/mips/lithium-mips.h
@@ -91,7 +91,6 @@ class LCodeGen;
   V(Integer32ToDouble)                       \
   V(InvokeFunction)                          \
   V(IsConstructCallAndBranch)                \
-  V(IsObjectAndBranch)                       \
   V(IsStringAndBranch)                       \
   V(IsSmiAndBranch)                          \
   V(IsUndetectableAndBranch)                 \
@@ -987,23 +986,6 @@ class LCompareMinusZeroAndBranch final : public LControlInstruction<1, 1> {
 };
 
 
-class LIsObjectAndBranch final : public LControlInstruction<1, 1> {
- public:
-  LIsObjectAndBranch(LOperand* value, LOperand* temp) {
-    inputs_[0] = value;
-    temps_[0] = temp;
-  }
-
-  LOperand* value() { return inputs_[0]; }
-  LOperand* temp() { return temps_[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:
   LIsStringAndBranch(LOperand* value, LOperand* temp) {