bpo-9566: Fix compiler warnings in pyexpat.c (GH-10654)

Explicit cast a pointer difference (intptr_t) to int to fix two warnings on 64-bit Windows: Modules\pyexpat.c(1181): warning C4244: 'initializing': conversion from '__int64' to 'int', possible loss of data Modules\pyexpat.c(1192): warning C4244: 'initializing': conversion from '__int64' to 'int', possible loss of data

Author: vstinner

Modules/pyexpat.c

@@ -1178,7 +1178,8 @@ xmlparse_dealloc(xmlparseobject *self)
 static PyObject *
 xmlparse_handler_getter(xmlparseobject *self, struct HandlerInfo *hi)
 {
- int handlernum = hi - handler_info;
+ assert((hi - handler_info) < (Py_ssize_t)Py_ARRAY_LENGTH(handler_info));
+ int handlernum = (int)(hi - handler_info);
  PyObject *result = self->handlers[handlernum];
  if (result == NULL)
  result = Py_None;
@@ -1189,7 +1190,8 @@ xmlparse_handler_getter(xmlparseobject *self, struct HandlerInfo *hi)
 static int
 xmlparse_handler_setter(xmlparseobject *self, PyObject *v, struct HandlerInfo *hi)
 {
- int handlernum = hi - handler_info;
+ assert((hi - handler_info) < (Py_ssize_t)Py_ARRAY_LENGTH(handler_info));
+ int handlernum = (int)(hi - handler_info);
  if (v == NULL) {
  PyErr_SetString(PyExc_RuntimeError, "Cannot delete attribute");
  return -1;