Don't use the keyed slow stub for named handlers.

src/ic/s390/ic-s390.cc

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #if V8_TARGET_ARCH_S390
 
 #include "src/ic/ic.h"
 #include "src/codegen.h"
 #include "src/ic/ic-compiler.h"
 #include "src/ic/stub-cache.h"
@@ skipping 655 matching lines @@
   DCHECK(!AreAliased(vector, slot, r7, r8, r9, ip));
   Handle<TypeFeedbackVector> dummy_vector =
       TypeFeedbackVector::DummyVector(masm->isolate());
   int slot_index = dummy_vector->GetIndex(
       FeedbackVectorSlot(TypeFeedbackVector::kDummyKeyedStoreICSlot));
   __ LoadRoot(vector, Heap::kDummyVectorRootIndex);
   __ LoadSmiLiteral(slot, Smi::FromInt(slot_index));
 
   Code::Flags flags =
       Code::RemoveHolderFromFlags(Code::ComputeHandlerFlags(Code::STORE_IC));
-  masm->isolate()->stub_cache()->GenerateProbe(masm, Code::STORE_IC, flags,
-                                               receiver, key, r7, r8, r9, ip);
+  masm->isolate()->stub_cache()->GenerateProbe(
+      masm, Code::KEYED_STORE_IC, flags, receiver, key, r7, r8, r9, ip);
   // Cache miss.
   __ b(&miss);
 
   // Extra capacity case: Check if there is extra capacity to
   // perform the store and update the length. Used for adding one
   // element to the array by writing to array[array.length].
   __ bind(&extra);
   // Condition code from comparing key and array length is still available.
   __ bne(&slow);  // Only support writing to writing to array[array.length].
   // Check for room in the elements backing store.
@@ skipping 200 matching lines @@
     patcher.masm()->brcl(cc, Operand((branch_instr & 0xffffffff) << 1));
   } else {
     DCHECK(false);
   }
 }
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_S390