This works by not caching the handle and instead getting the handle from
the file descriptor each time, so that if the actual handle changes by
fd redirection closing/opening the console handle beneath our feet, we
will keep working correctly.
- `_Py_EncodeLocaleRaw`, which is private by name, undocumented,
and wasn't exported in `python3.dll`, is moved to a private header.
- `_Py_HashSecret_Initialized`, again private by name, undocumented,
and not exported in `python3.dll`, is excluded with `Py_LIMITED_API`.
- `PyMarshal_*` and `PyMember_*One` functions, declared in private headers and
not exported in `python3.dll`, are removed from `Doc/data/stable_abi.dat`.
- `PyMem_Calloc` which *was* exported in `python3dll.c`, is moved to public
headers where it joins its other `PyMem_*` friends.
Only the last change is documented in the blurb; others are not user-visible.
(Nothing uses `Doc/data/stable_abi.dat` yet.)
https://bugs.python.org/issue43795
Move CPython C API from Include/fileutils.h into a new
Include/cpython/fileutils.h header file which is included by
Include/fileutils.h.
Exclude the following private symbols from the limited C API:
* _Py_error_handler
* _Py_GetErrorHandler()
* _Py_DecodeLocaleEx()
* _Py_EncodeLocaleEx()
