gh-112026: Restore removed private C API

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Restore removed private C API functions, macros and structures which have no simple replacement for now:

• _PyDict_GetItem_KnownHash()
• _PyDict_NewPresized()
• _PyHASH_BITS
• _PyHASH_IMAG
• _PyHASH_INF
• _PyHASH_MODULUS
• _PyHASH_MULTIPLIER
• _PyLong_Copy()
• _PyLong_FromDigits()
• _PyLong_New()
• _PyLong_Sign()
• _PyObject_CallMethodId()
• _PyObject_CallMethodNoArgs()
• _PyObject_CallMethodOneArg()
• _PyObject_CallOneArg()
• _PyObject_EXTRA_INIT
• _PyObject_FastCallDict()
• _PyObject_GetAttrId()
• _PyObject_Vectorcall()
• _PyObject_VectorcallMethod()
• _PyStack_AsDict()
• _PyThread_CurrentFrames()
• _PyUnicodeWriter structure
• _PyUnicodeWriter_Dealloc()
• _PyUnicodeWriter_Finish()
• _PyUnicodeWriter_Init()
• _PyUnicodeWriter_Prepare()
• _PyUnicodeWriter_PrepareKind()
• _PyUnicodeWriter_WriteASCIIString()
• _PyUnicodeWriter_WriteChar()
• _PyUnicodeWriter_WriteLatin1String()
• _PyUnicodeWriter_WriteStr()
• _PyUnicodeWriter_WriteSubstring()
• _PyUnicode_AsString()
• _PyUnicode_FromId()
• _PyVectorcall_Function()
• _Py_IDENTIFIER()
• _Py_c_abs()
• _Py_c_diff()
• _Py_c_neg()
• _Py_c_pow()
• _Py_c_prod()
• _Py_c_quot()
• _Py_c_sum()
• _Py_static_string()
• _Py_static_string_init()

• Issue: [C API] Revert of private functions removed in Python 3.13 causing most problems #112026

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Last weeks, other functions removed in Python 3.13 were reported as causing problems.

The following functions were already restored since Python 3.13 alpha1:

• _PyLong_AsByteArray()
• _PyLong_FromByteArray()

Not restored, use new public functions instead:

• _PyObject_VisitManagedDict(): use PyObject_VisitManagedDict()
• _PyObject_ClearManagedDict(): use PyObject_ClearManagedDict()
• _PyThreadState_UncheckedGet(): use PyThreadState_GetUnchecked()
• _PyList_Extend(): use PyList_Extend(), different API
• _PyDict_Pop(): use PyDict_Pop(), different API

Not restored:

• _PyDict_ContainsId()
• _PyDict_DelItemId()
• _PyDict_GetItemIdWithError()
• _PyDict_SetItemId()
• _PyEval_GetBuiltinId()
• _PyLong_NumBits()
• _PyObject_CallMethodIdNoArgs()
• _PyObject_CallMethodIdObjArgs()
• _PyObject_CallMethodIdOneArg()
• _PyObject_LookupSpecialId()
• _PyObject_SetAttrId()
• _PyObject_VectorcallMethodId()
• _PyTime_AsSecondsDouble()
• _PyTime_FromTimeval()
• _PyTime_GetSystemClock()
• _PyTime_t
• _PyType_LookupId()
• _PyUnicode_EqualToASCIIId()

Pending PR:

• _Py_HashDouble(): gh-111545: Add PyHash_Double() function #112095
• _Py_HashPointer(): gh-111545: Add Py_HashPointer() function #112096

Removed:

• _PyErr_WriteUnraisable()

Not restored, deprecated:

• 2to3 module removal
• <ctype.h>
• <unistd.h>
• Logger.warn()
• PyCFunction_Call()
• PyEval_AcquireLock()
• PyEval_CallObject()
• PyEval_InitThreads()
• PyEval_ReleaseLock()
• PyObject_AsCharBuffer()
• PyObject_AsReadBuffer()
• PyObject_AsWriteBuffer()
• PySys_SetArgv()
• PySys_SetArgvEx()
• PySys_SetPath()
• PyUnicode_AS_DATA
• PyUnicode_AS_UNICODE()
• PyUnicode_GetSize()
• Py_SetProgramName()
• Py_TRASHCAN_SAFE_BEGIN and Py_TRASHCAN_SAFE_END
• importlib.resources removed functions
• locale.resetlocale()
• typing.re
• unittest-related removals

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With this change, I can successfully install cffi 1.16.0 and numpy 1.26.2.

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With this change, I can successfully install cffi 1.16.0 and numpy 1.26.2.

Oh, on Fedora 39, GCC only emits a warning when using an undefined function, and so the build was successful, but numpy calls a function which doesn't exist anymore! My script to test numpy:

set -e -x
wget https://files.pythonhosted.org/packages/dd/2b/205ddff2314d4eea852e31d53b8e55eb3f32b292efc3dd86bd827ab9019d/numpy-1.26.2.tar.gz
rm -rf numpy-1.26.2
tar -xf numpy-1.26.2.tar.gz
cd numpy-1.26.2/
/opt/py313/bin/python3.13 -m venv env
export CFLAGS='-Werror=implicit-function-declaration'
export LANG=
env/bin/python -m pip install . -v

In fact, 3 other changes are needed by numpy (UPDATE: done):

• Restore #include <ctype.h>: gh-112026: Add again <unistd.h> include in Python.h #112046
• Restore removed _PyDict_GetItemStringWithError() function.
• Restore _Py_HashDouble() function.

With these additional changes, I can successfully build numpy with -Werror=implicit-function-declaration compiler flag.

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Restore _Py_HashDouble() function.

I updated the PR to restore _Py_HashDouble() and _Py_HashPointer() functions.