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

src/ic/s390/handler-compiler-s390.cc

Index: src/ic/s390/handler-compiler-s390.cc
diff --git a/src/ic/s390/handler-compiler-s390.cc b/src/ic/s390/handler-compiler-s390.cc
index b8ca7aca532d9f2fdba4ffe5ced37d5dc6a7b131..1206a249a8682a91392f866267ad430018151a3f 100644
--- a/src/ic/s390/handler-compiler-s390.cc
+++ b/src/ic/s390/handler-compiler-s390.cc
@@ -703,7 +703,7 @@ Handle<Code> NamedStoreHandlerCompiler::CompileStoreCallback(
   __ TailCallRuntime(Runtime::kStoreCallbackProperty);
 
   // Return the generated code.
-  return GetCode(kind(), Code::FAST, name);
+  return GetCode(kind(), name);
 }
 
 Register NamedStoreHandlerCompiler::value() {
@@ -740,7 +740,7 @@ Handle<Code> NamedLoadHandlerCompiler::CompileLoadGlobal(
   FrontendFooter(name, &miss);
 
   // Return the generated code.
-  return GetCode(kind(), Code::NORMAL, name);
+  return GetCode(kind(), name);
 }
 
 #undef __