Use 'isArrayElementWritable' instead of 'isArrayElementModifiable'.

Author: fangerer

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/foreign/AccessForeignItemNodes.java

@@ -239,7 +239,7 @@ public Object doForeignObject(Object object, Object idx, Object value,
         }
 
         private void writeForeignValue(Object object, int idx, Object value, InteropLibrary lib) throws UnsupportedMessageException, UnsupportedTypeException {
-            if (lib.isArrayElementModifiable(object, idx)) {
+            if (lib.isArrayElementWritable(object, idx)) {
                 try {
                     lib.writeArrayElement(object, idx, value);
                     return;