No need for explicit accepts() for DelegatedArrayStorage and SharedArrayStorage

* Truffle libraries automatically merge the "nested" library for the backing store,
  i.e., `receiverStorageArrayStoreLibrary_ = ARRAY_STORE_LIBRARY_.create((castReceiver.storage));`
  in the generated DelegatedArrayStorageGen.ArrayStoreLibraryExports.Cached#Cached
  because `storage` is a final field and `@CachedLibrary("this.storage")` is used in messages.

Author: eregon

src/main/java/org/truffleruby/core/array/library/DelegatedArrayStorage.java

@@ -48,12 +48,6 @@ public DelegatedArrayStorage(Object storage, int offset, int length) {
         this.length = length;
     }
 
-    @ExportMessage
-    protected static boolean accepts(DelegatedArrayStorage store,
-            @CachedLibrary("store.storage") ArrayStoreLibrary stores) {
-        return true;
-    }
-
     @ExportMessage
     protected Object read(int index,
             @CachedLibrary("this.storage") ArrayStoreLibrary stores) {

src/main/java/org/truffleruby/core/array/library/SharedArrayStorage.java

@@ -66,12 +66,6 @@ public boolean allElementsShared(int size) {
         return true;
     }
 
-    @ExportMessage
-    protected static boolean accepts(SharedArrayStorage store,
-            @CachedLibrary("store.storage") ArrayStoreLibrary stores) {
-        return true;
-    }
-
     @ExportMessage
     protected Object read(int index,
             @CachedLibrary("this.storage") ArrayStoreLibrary stores) {