remove usage of internal truffle class

Author: timfel

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/common/DynamicObjectStorage.java

@@ -57,6 +57,7 @@
 import com.oracle.graal.python.nodes.object.BuiltinClassProfiles.IsBuiltinObjectProfile;
 import com.oracle.graal.python.nodes.util.CastToTruffleStringNode;
 import com.oracle.graal.python.runtime.sequence.storage.MroSequenceStorage;
+import com.oracle.graal.python.util.PythonUtils;
 import com.oracle.truffle.api.CompilerDirectives.TruffleBoundary;
 import com.oracle.truffle.api.dsl.Bind;
 import com.oracle.truffle.api.dsl.Cached;
@@ -79,7 +80,6 @@
 import com.oracle.truffle.api.profiles.InlinedBranchProfile;
 import com.oracle.truffle.api.profiles.InlinedConditionProfile;
 import com.oracle.truffle.api.strings.TruffleString;
-import com.oracle.truffle.object.ShapeImpl;
 
 /**
  * This storage keeps a reference to the MRO when used for a type dict. Writing to this storage will
@@ -124,7 +124,7 @@ protected static Object[] keyArray(DynamicObjectStorage self) {
     }
 
     protected static Object[] keyArray(Shape shape) {
-        return ((ShapeImpl) shape).getKeyArray();
+        return shape.getKeyList().toArray();
     }
 
     @GenerateUncached