Log what target we have when we're looking up a vtable slot

Summary: There's a bunch of errors coming out of this where we're failing to find the v-table slot.  It seems likely that we either have the slot patched or that the type isn't actually being defined statically for some reason.  This increases what we report for the error so we can have a chance of figuring out what the issue is.

Reviewed By: alexmalyshev

Differential Revision: D55702279

fbshipit-source-id: c7031fc86d663e5c6db11bf424d41935d62a4471

cinderx/StaticPython/classloader.c

@@ -3759,8 +3759,9 @@ classloader_init_slot(PyObject *path)
     PyObject *new_index = PyDict_GetItem(slot_map, slot_name);
     if (new_index == NULL) {
         PyErr_Format(
-            PyExc_RuntimeError, "unable to resolve v-table slot '%R' in %s",
-                slot_name, target_type->tp_name);
+            PyExc_RuntimeError, "unable to resolve v-table slot %R in %s for %s (%R) is_static: %s used: %s",
+                slot_name, target_type->tp_name, Py_TYPE(cur)->tp_name, cur, 
+                is_static_type(target_type) ? "true" : "false", used_in_vtable(cur) ? "true" : "false");
         Py_DECREF(target_type);
         Py_DECREF(cur);
         return -1;