Array constructor expects AllocationSite or undefined as feedback.

src/a64/builtins-a64.cc

Index: src/a64/builtins-a64.cc
diff --git a/src/a64/builtins-a64.cc b/src/a64/builtins-a64.cc
index 0641c10d1358e8f3c97406f43fe9e2bbd1deecb1..f4996d77c6d26d3d56654351a73473c0b7bb0d8d 100644
--- a/src/a64/builtins-a64.cc
+++ b/src/a64/builtins-a64.cc
@@ -149,9 +149,7 @@ void Builtins::Generate_ArrayCode(MacroAssembler* masm) {
   }
 
   // Run the native code for the Array function called as a normal function.
-  Handle<Object> megamorphic_sentinel =
-      TypeFeedbackInfo::MegamorphicSentinel(masm->isolate());
-  __ Mov(x2, Operand(megamorphic_sentinel));
+  __ LoadRoot(x2, Heap::kUndefinedValueRootIndex);
   ArrayConstructorStub stub(masm->isolate());
   __ TailCallStub(&stub);
 }
@@ -728,9 +726,7 @@ static void Generate_JSEntryTrampolineHelper(MacroAssembler* masm,
     __ Mov(x0, argc);
     if (is_construct) {
       // No type feedback cell is available.
-      Handle<Object> megamorphic_sentinel =
-          TypeFeedbackInfo::MegamorphicSentinel(masm->isolate());
-      __ Mov(x2, Operand(megamorphic_sentinel));
+      __ LoadRoot(x2, Heap::kUndefinedValueRootIndex);
 
       CallConstructStub stub(NO_CALL_FUNCTION_FLAGS);
       __ CallStub(&stub);