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

src/s390/code-stubs-s390.cc

Index: src/s390/code-stubs-s390.cc
diff --git a/src/s390/code-stubs-s390.cc b/src/s390/code-stubs-s390.cc
index d1df07548d31690f1b16a0bf801d35264dcc5ec4..20f8b54cb11b959cc816a8e1f372b78975c65c43 100644
--- a/src/s390/code-stubs-s390.cc
+++ b/src/s390/code-stubs-s390.cc
@@ -3908,8 +3908,8 @@ void LoadICStub::GenerateImpl(MacroAssembler* masm, bool in_frame) {
   __ bind(&not_array);
   __ CompareRoot(feedback, Heap::kmegamorphic_symbolRootIndex);
   __ bne(&miss);
-  Code::Flags code_flags = Code::RemoveTypeAndHolderFromFlags(
-      Code::ComputeHandlerFlags(Code::LOAD_IC));
+  Code::Flags code_flags =
+      Code::RemoveHolderFromFlags(Code::ComputeHandlerFlags(Code::LOAD_IC));
   masm->isolate()->stub_cache()->GenerateProbe(masm, Code::LOAD_IC, code_flags,
                                                receiver, name, feedback,
                                                receiver_map, scratch1, r9);
@@ -4043,8 +4043,8 @@ void VectorStoreICStub::GenerateImpl(MacroAssembler* masm, bool in_frame) {
   __ bind(&not_array);
   __ CompareRoot(feedback, Heap::kmegamorphic_symbolRootIndex);
   __ bne(&miss);
-  Code::Flags code_flags = Code::RemoveTypeAndHolderFromFlags(
-      Code::ComputeHandlerFlags(Code::STORE_IC));
+  Code::Flags code_flags =
+      Code::RemoveHolderFromFlags(Code::ComputeHandlerFlags(Code::STORE_IC));
   masm->isolate()->stub_cache()->GenerateProbe(
       masm, Code::STORE_IC, code_flags, receiver, key, feedback, receiver_map,
       scratch1, scratch2);