make PExternalFunctionWrapper a plain interop object

Author: timfel

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/modules/PythonCextBuiltins.java

@@ -1583,19 +1583,17 @@ Object call(Object self, PBuiltinFunction function) {
         }
     }
 
-    public abstract static class PExternalFunctionWrapper extends PythonBuiltinObject {
+    public abstract static class PExternalFunctionWrapper extends Object implements TruffleObject {
 
         private final Supplier<ConvertArgsToSulongNode> convertArgsNodeSupplier;
         private final Supplier<CheckFunctionResultNode> checkFunctionResultNodeSupplier;
 
         public PExternalFunctionWrapper(Supplier<ConvertArgsToSulongNode> convertArgsNodeSupplier) {
-            super(PythonBuiltinClassType.PythonObject, PythonBuiltinClassType.PythonObject.getInstanceShape());
             this.convertArgsNodeSupplier = convertArgsNodeSupplier;
             this.checkFunctionResultNodeSupplier = DefaultCheckFunctionResultNodeGen::create;
         }
 
         public PExternalFunctionWrapper(Supplier<ConvertArgsToSulongNode> convertArgsNodeSupplier, Supplier<CheckFunctionResultNode> checkFunctionResultNodeSupplier) {
-            super(PythonBuiltinClassType.PythonObject, PythonBuiltinClassType.PythonObject.getInstanceShape());
             this.convertArgsNodeSupplier = convertArgsNodeSupplier;
             this.checkFunctionResultNodeSupplier = checkFunctionResultNodeSupplier;
         }
@@ -1611,11 +1609,6 @@ protected ConvertArgsToSulongNode createConvertArgsToSulongNode() {
         public CheckFunctionResultNode getCheckFunctionResultNode() {
             return checkFunctionResultNodeSupplier.get();
         }
-
-        @Override
-        public int compareTo(Object o) {
-            throw CompilerDirectives.shouldNotReachHere();
-        }
     }
 
     @Builtin(name = "METH_DIRECT")