Correctly compute byte size of buffer decorator.

Author: fangerer

graalpython/com.oracle.graal.python.cext/src/memoryobject.c

@@ -44,5 +44,5 @@ PyTypeObject PyMemoryView_Type = PY_TRUFFLE_TYPE("memoryview", &PyType_Type, Py_
 PyTypeObject PyBuffer_Type = PY_TRUFFLE_TYPE("buffer", &PyType_Type, Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC, sizeof(PyBufferDecorator));
 
 int bufferdecorator_getbuffer(PyBufferDecorator *self, Py_buffer *view, int flags) {
-    return PyBuffer_FillInfo(view, (PyObject*)self, polyglot_get_member(self, "buf_delegate"), PyObject_Size((PyObject *)self), self->readonly, flags);
+    return PyBuffer_FillInfo(view, (PyObject*)self, polyglot_get_member(self, "buf_delegate"), PyObject_Size((PyObject *)self) * sizeof(PyObject*), self->readonly, flags);
 }

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/memoryview/BufferBuiltins.java

@@ -133,7 +133,7 @@ protected Object doGeneric(Object self, Object idx) {
     public abstract static class LenNode extends PythonUnaryBuiltinNode {
 
         @Specialization
-        public Object iter(PBuffer self,
+        public Object len(PBuffer self,
                         @Cached("create(__LEN__)") LookupAndCallUnaryNode callLenNode) {
             return callLenNode.executeObject(self.getDelegate());
         }