Use a dictionary-mode code cache on the map rather than a dual system.

src/ic/arm64/ic-arm64.cc

Index: src/ic/arm64/ic-arm64.cc
diff --git a/src/ic/arm64/ic-arm64.cc b/src/ic/arm64/ic-arm64.cc
index 726a68e45f4ab4f085e2abb3e6d8dfb210b7f107..40082bbbecba7c70fce70464d7a5d92abce67ed0 100644
--- a/src/ic/arm64/ic-arm64.cc
+++ b/src/ic/arm64/ic-arm64.cc
@@ -394,8 +394,8 @@ static void GenerateKeyedLoadWithNameKey(MacroAssembler* masm, Register key,
   __ LoadRoot(vector, Heap::kDummyVectorRootIndex);
   __ Mov(slot, Operand(Smi::FromInt(slot_index)));
 
-  Code::Flags flags = Code::RemoveTypeAndHolderFromFlags(
-      Code::ComputeHandlerFlags(Code::LOAD_IC));
+  Code::Flags flags =
+      Code::RemoveHolderFromFlags(Code::ComputeHandlerFlags(Code::LOAD_IC));
   masm->isolate()->stub_cache()->GenerateProbe(masm, Code::KEYED_LOAD_IC, flags,
                                                receiver, key, scratch1,
                                                scratch2, scratch3, scratch4);
@@ -673,8 +673,8 @@ void KeyedStoreIC::GenerateMegamorphic(MacroAssembler* masm,
   __ LoadRoot(vector, Heap::kDummyVectorRootIndex);
   __ Mov(slot, Operand(Smi::FromInt(slot_index)));
 
-  Code::Flags flags = Code::RemoveTypeAndHolderFromFlags(
-      Code::ComputeHandlerFlags(Code::STORE_IC));
+  Code::Flags flags =
+      Code::RemoveHolderFromFlags(Code::ComputeHandlerFlags(Code::STORE_IC));
   masm->isolate()->stub_cache()->GenerateProbe(masm, Code::STORE_IC, flags,
                                                receiver, key, x5, x6, x7, x8);
   // Cache miss.
@@ -733,8 +733,8 @@ void StoreIC::GenerateMegamorphic(MacroAssembler* masm) {
                      x5, x6));
 
   // Probe the stub cache.
-  Code::Flags flags = Code::RemoveTypeAndHolderFromFlags(
-      Code::ComputeHandlerFlags(Code::STORE_IC));
+  Code::Flags flags =
+      Code::RemoveHolderFromFlags(Code::ComputeHandlerFlags(Code::STORE_IC));
   masm->isolate()->stub_cache()->GenerateProbe(masm, Code::STORE_IC, flags,
                                                receiver, name, x3, x4, x5, x6);