Revert 15635: Turn ElementsTransitionAndStore stub into a HydrogenCodeStub

src/elements-kind.h

Index: src/elements-kind.h
diff --git a/src/elements-kind.h b/src/elements-kind.h
index 151dde47e1020b63595396ac69f3a3ce5f34c3bf..da151924be20dd389a7e2995db505e9c00166fff 100644
--- a/src/elements-kind.h
+++ b/src/elements-kind.h
@@ -229,15 +229,6 @@ inline bool CanTransitionToMoreGeneralFastElementsKind(
 }
 
 
-inline bool DoesTransitionChangeElementsBufferFormat(ElementsKind from_kind,
-                                                     ElementsKind to_kind) {
-  return (IsFastSmiElementsKind(from_kind) &&
-          IsFastDoubleElementsKind(to_kind)) ||
-      (IsFastDoubleElementsKind(from_kind) &&
-       IsFastObjectElementsKind(to_kind));
-}
-
-
 } }  // namespace v8::internal
 
 #endif  // V8_ELEMENTS_KIND_H_