[stubs] Port KeyedStoreIC_Megamorphic stub to Turbofan

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 68b2aa6354bbb11f5aa48f63419dbe786ea84474..1ed5615c4205604bb05b801db870e6d60c4514cf 100644
--- a/src/code-stub-assembler.h
+++ b/src/code-stub-assembler.h
@@ -1118,6 +1118,10 @@ class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
                                          ElementsKind kind, ParameterMode mode,
                                          int base_size = 0);
 
+ protected:
+  void HandleStoreICHandlerCase(const StoreICParameters* p,
+                                compiler::Node* handler, Label* miss);
+
  private:
   friend class CodeStubArguments;
 
@@ -1159,9 +1163,6 @@ class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
                                    compiler::Node* value,
                                    bool transition_to_field, Label* miss);
 
-  void HandleStoreICHandlerCase(const StoreICParameters* p,
-                                compiler::Node* handler, Label* miss);
-
   compiler::Node* TryToIntptr(compiler::Node* key, Label* miss);
   void EmitFastElementsBoundsCheck(compiler::Node* object,
                                    compiler::Node* elements,