ctypes defines a number of global symbols which aren't
namespace-prefixed, such as AllocFunctionCallback, FreeClosure, GetType,
IsSimpleSubType, MallocClosure, _AddTraceback, _CallProc,
alloc_format_string, conversion_mode_encoding, conversion_mode_errors,
get_error_object, getentry, module_methods (there are more, but the
other ones can be understood as being unambiguously prefixed, such as
with CData, CField, StgDict).

It would be good if these symbols either are changed to static, or get a
proper Py/_Py prefix.