If the first PyUnicode_DecodeUTF8() call fails in structseq_repr(),
_PyUnicodeWriter_Dealloc() will be called on an uninitialized
_PyUnicodeWriter.

bpo-36256: Fix bug in parsermodule when parsing if statements

In the parser module, when validating nodes before starting the parsing with to create a ST in "parser_newstobject" there is a problem that appears when two arcs in the same DFA state has transitions with labels with the same type. For example, the DFA for if_stmt has a state with
two labels with the same type: "elif" and "else" (type NAME). The algorithm tries one by one the arcs until the label that starts the arc transition has a label with the same type of the current child label we are trying to accept. In this case, the arc for "elif" comes before the arc for "else"and passes this test (because the current child label is "else" and has the same type as "elif"). This lead to expecting a namedexpr_test (305) instead of a colon (11). The solution is to compare also the string representation (in case there is one) of the labels to see if the transition that we have is the correct one.

Also fixes venvs from the build directory on Windows.

Currently, when arguments on Parser/asdl_c.py are parsed
``ìf`` sentence is used. This PR Propose to use ``elif``
to avoid multiple evaluting of the ifs.





https://bugs.python.org/issue36385

* Improve coverage.
* Note inherent limitations of the accuracy tests


https://bugs.python.org/issue36324

https://bugs.python.org/issue36374

_PyCoreConfig_ReadFromArgv() now reuses the code parsing command line
options from preconfig.c.

https://bugs.python.org/issue23984

Don't override parameters which are already set by the user.

* Add _PyRuntime.pre_initialized: set to 1 when Python
  is pre-initialized
* Add _Py_PreInitialize() and _Py_PreInitializeFromPreConfig().
* _PyCoreConfig_Read() now calls  _Py_PreInitialize().
* Move _PyPreConfig_GetGlobalConfig() and
  _PyCoreConfig_GetGlobalConfig() calls from main.c to preconfig.c
  and coreconfig.c.

https://bugs.python.org/issue36362

No longer limit repr(structseq) to 512 bytes. Use _PyUnicodeWriter
for better performance and to write directly Unicode rather than
encoding repr() value to UTF-8 and then decoding from UTF-8.

Calling _PyRuntime_Initialize() after _PyRuntime_Finalize() now re-initializes
_PyRuntime structure. Previously, _PyRuntime_Initialize() did
nothing in that case.

https://bugs.python.org/issue36324

* _PyPathConfig_ComputeSysPath0() now returns 0 if argv is empty.
* Cleanup also _PyPathConfig_ComputeSysPath0() code: move variables
  definitions closer to where they are used.

At Python initialization, the current directory is no longer
prepended to sys.path if it has been removed.

Rename _PyPathConfig_ComputeArgv0() to
_PyPathConfig_ComputeSysPath0() to avoid confusion between argv[0]
and sys.path[0].

Ensure that _PyRuntime_Finalize() is always call. This change fix a
few memory leaks when running "python3 -V".

When Python is compiled with Valgrind support, release Unicode
interned strings at exit in _PyUnicode_Fini().

* Rename _Py_ReleaseInternedUnicodeStrings() to
  unicode_release_interned() and make it private.
* unicode_release_interned() is now called from _PyUnicode_Fini():
  it must be called with a running Python thread state for TRASHCAN,
  it cannot be called from pymain_free().
* Don't display statistics on interned strings at exit anymore

_PyEval_FiniThreads() now free the pending lock.

Modules/_sqlite/cursor.c uses "y#" format.
It didn't declare PY_SSIZE_T_CLEAN, but the argument is Py_ssize_t already.

_PyPreConfig_Read() now free 'old_old' at exit.

* Use Py_ARRAY_LENGTH() rather than hardcoded MAXPATHLEN in getpath.c.
* Pass string length to functions modifying strings.

Python initialization now fails if decoding pybuilddir.txt
configuration file fails at startup.

_PyPathConfig_Calculate() now reports memory allocation failure and
decoding error on decoding pybuilddir.txt content from
UTF-8/surrogateescape.

Replace Py_FatalError() with _PyInitError to let the caller handle
the fatal error.

bpo-36301, bpo-36333:

* Fix memory allocator used by _PyPathConfig_ClearGlobal():
  force the default allocator.
* _PyPreConfig_ReadFromArgv(): free init_ctype_locale memory.
* pymain_main(): call pymain_free() on init error
Co-Authored-By: Stéphane Wirtel <stephane@wirtel.be>