[cleanup] CSA: add helpers for accessing details/value via key_index

src/code-stub-assembler.h

Index: src/code-stub-assembler.h
diff --git a/src/code-stub-assembler.h b/src/code-stub-assembler.h
index edc239352b151458f756488065b189da5c43182d..937196fe02849632fd3529e9a7abeb58ddbeb8b2 100644
--- a/src/code-stub-assembler.h
+++ b/src/code-stub-assembler.h
@@ -885,6 +885,22 @@ class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
   Node* EntryToIndex(Node* entry) {
     return EntryToIndex<Dictionary>(entry, Dictionary::kEntryKeyIndex);
   }
+  // Loads the details for the entry with the given key_index.
+  // Returns an untagged int32.
+  template <class ContainerType>
+  Node* LoadDetailsForKeyIndex(Node* container, Node* key_index);
+  // Loads the value for the entry with the given key_index.
+  // Returns a tagged value.
+  template <class ContainerType>
+  Node* LoadValueForKeyIndex(Node* container, Node* key_index);
+  // Stores the details for the entry with the given key_index.
+  // |details| must be a Smi.
+  template <class ContainerType>
+  void StoreDetailsForKeyIndex(Node* container, Node* key_index, Node* details);
+  // Stores the value for the entry with the given key_index.
+  template <class ContainerType>
+  void StoreValueForKeyIndex(Node* container, Node* key_index, Node* value);
+
   // Calculate a valid size for the a hash table.
   Node* HashTableComputeCapacity(Node* at_least_space_for);