Revert of [refactoring] Split CodeAssemblerState out of CodeAssembler

src/ic/keyed-store-generic.cc

Index: src/ic/keyed-store-generic.cc
diff --git a/src/ic/keyed-store-generic.cc b/src/ic/keyed-store-generic.cc
index 76495bc671c6624169d156bcb18b6efd867d08d9..30faba85e949ba4d5d758e1a068111720fa5d7ea 100644
--- a/src/ic/keyed-store-generic.cc
+++ b/src/ic/keyed-store-generic.cc
@@ -4,9 +4,8 @@
 
 #include "src/ic/keyed-store-generic.h"
 
-#include "src/code-stub-assembler.h"
+#include "src/compiler/code-assembler.h"
 #include "src/contexts.h"
-#include "src/interface-descriptors.h"
 #include "src/isolate.h"
 
 namespace v8 {
@@ -16,9 +15,6 @@
 
 class KeyedStoreGenericAssembler : public CodeStubAssembler {
  public:
-  explicit KeyedStoreGenericAssembler(compiler::CodeAssemblerState* state)
-      : CodeStubAssembler(state) {}
-
   void KeyedStoreGeneric(const StoreICParameters* p,
                          LanguageMode language_mode);
 
@@ -63,23 +59,17 @@
                                 Node* current_elements_kind, Node* context,
                                 ElementsKind packed_kind,
                                 ElementsKind packed_kind_2, Label* bailout);
+
+  // Do not add fields, so that this is safe to reinterpret_cast to CSA.
 };
 
-void KeyedStoreGenericGenerator::Generate(compiler::CodeAssemblerState* state,
-                                          LanguageMode language_mode) {
-  typedef StoreWithVectorDescriptor Descriptor;
-  KeyedStoreGenericAssembler assembler(state);
-
-  Node* receiver = assembler.Parameter(Descriptor::kReceiver);
-  Node* name = assembler.Parameter(Descriptor::kName);
-  Node* value = assembler.Parameter(Descriptor::kValue);
-  Node* slot = assembler.Parameter(Descriptor::kSlot);
-  Node* vector = assembler.Parameter(Descriptor::kVector);
-  Node* context = assembler.Parameter(Descriptor::kContext);
-
-  CodeStubAssembler::StoreICParameters p(context, receiver, name, value, slot,
-                                         vector);
-  assembler.KeyedStoreGeneric(&p, language_mode);
+void KeyedStoreGenericGenerator::Generate(
+    CodeStubAssembler* assembler, const CodeStubAssembler::StoreICParameters* p,
+    LanguageMode language_mode) {
+  STATIC_ASSERT(sizeof(CodeStubAssembler) ==
+                sizeof(KeyedStoreGenericAssembler));
+  auto assm = reinterpret_cast<KeyedStoreGenericAssembler*>(assembler);
+  assm->KeyedStoreGeneric(p, language_mode);
 }
 
 void KeyedStoreGenericAssembler::BranchIfPrototypesHaveNonFastElements(