[runtime] Remove useless %_IsUndetectableObject 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 d0719ffdfff419f80c80fd434809ec011bff2084..dea09fcddbfc8a16c88675d7420497033da6bf85 100644
--- a/src/full-codegen/arm64/full-codegen-arm64.cc
+++ b/src/full-codegen/arm64/full-codegen-arm64.cc
@@ -3139,31 +3139,6 @@ void FullCodeGenerator::EmitIsSimdValue(CallRuntime* expr) {
 }
 
 
-void FullCodeGenerator::EmitIsUndetectableObject(CallRuntime* expr) {
-  ASM_LOCATION("FullCodeGenerator::EmitIsUndetectableObject");
-  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);
-  __ Ldr(x10, FieldMemOperand(x0, HeapObject::kMapOffset));
-  __ Ldrb(x11, FieldMemOperand(x10, Map::kBitFieldOffset));
-  __ Tst(x11, 1 << Map::kIsUndetectable);
-  PrepareForBailoutBeforeSplit(expr, true, if_true, if_false);
-  Split(ne, if_true, if_false, fall_through);
-
-  context()->Plug(if_true, if_false);
-}
-
-
 void FullCodeGenerator::EmitIsStringWrapperSafeForDefaultValueOf(
     CallRuntime* expr) {
   ZoneList<Expression*>* args = expr->arguments();