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 1b39782c28e71041dfc4526f4e1a19ea92d3015c..277eca5e6d4cca5edf728ad1090d378f44b86850 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 __