[runtime] Remove the redundant %_IsObject intrinsic.

src/full-codegen/arm64/full-codegen-arm64.cc

Index: src/full-codegen/arm64/full-codegen-arm64.cc
diff --git a/src/full-codegen/arm64/full-codegen-arm64.cc b/src/full-codegen/arm64/full-codegen-arm64.cc
index 6d98c15d3cf16f9156d25777ee1ed36b69da910d..37a59332406c3a959603c0457989a6f6135e8f35 100644
--- a/src/full-codegen/arm64/full-codegen-arm64.cc
+++ b/src/full-codegen/arm64/full-codegen-arm64.cc
@@ -3065,36 +3065,6 @@ void FullCodeGenerator::EmitIsNonNegativeSmi(CallRuntime* expr) {
 }
 
 
-void FullCodeGenerator::EmitIsObject(CallRuntime* expr) {
-  ZoneList<Expression*>* args = expr->arguments();
-  DCHECK(args->length() == 1);
-
-  VisitForAccumulatorValue(args->at(0));
-
-  Label materialize_true, materialize_false;
-  Label* if_true = NULL;
-  Label* if_false = NULL;
-  Label* fall_through = NULL;
-  context()->PrepareTest(&materialize_true, &materialize_false,
-                         &if_true, &if_false, &fall_through);
-
-  __ JumpIfSmi(x0, if_false);
-  __ JumpIfRoot(x0, Heap::kNullValueRootIndex, if_true);
-  __ Ldr(x10, FieldMemOperand(x0, HeapObject::kMapOffset));
-  // Undetectable objects behave like undefined when tested with typeof.
-  __ Ldrb(x11, FieldMemOperand(x10, Map::kBitFieldOffset));
-  __ Tbnz(x11, Map::kIsUndetectable, if_false);
-  __ Ldrb(x12, FieldMemOperand(x10, Map::kInstanceTypeOffset));
-  __ Cmp(x12, FIRST_NONCALLABLE_SPEC_OBJECT_TYPE);
-  __ B(lt, if_false);
-  __ Cmp(x12, LAST_NONCALLABLE_SPEC_OBJECT_TYPE);
-  PrepareForBailoutBeforeSplit(expr, true, if_true, if_false);
-  Split(le, if_true, if_false, fall_through);
-
-  context()->Plug(if_true, if_false);
-}
-
-
 void FullCodeGenerator::EmitIsSpecObject(CallRuntime* expr) {
   ZoneList<Expression*>* args = expr->arguments();
   DCHECK(args->length() == 1);