Replace messy _Py_wstrlist_xxx() functions with a new clean
_PyWstrList structure and new _PyWstrList_xxx() functions.
Changes:
* Add _PyCoreConfig.use_module_search_paths to decide if
_PyCoreConfig.module_search_paths should be computed or not, to
support empty search path list.
* _PyWstrList_Clear() sets length to 0 and items to NULL, whereas
_Py_wstrlist_clear() only freed memory.
* _PyWstrList_Append() returns an int, whereas _Py_wstrlist_append()
returned _PyInitError.
* _PyWstrList uses Py_ssize_t for the length, instead of int.
* Replace (int, wchar_t**) with _PyWstrList in:
* _PyPreConfig
* _PyCoreConfig
* _PyPreCmdline
* _PyCmdline
* Replace "int orig_argv; wchar_t **orig_argv;"
with "_PyWstrList orig_argv".
* _PyCmdline and _PyPreCmdline now also copy wchar_argv.
* Rename _PyArgv_Decode() to _PyArgv_AsWstrList().
* PySys_SetArgvEx() now pass the fixed (argc, argv) to
_PyPathConfig_ComputeArgv0() (don't pass negative argc or NULL
argv).
* _PyOS_GetOpt() uses Py_ssize_t
bpo-34247, bpo-36142: The PYTHONMALLOC environment variable has the
priority over PYTHONDEV env var and "-X dev" command line option.
For example, PYTHONMALLOC=malloc PYTHONDEVMODE=1 sets the memory
allocators to "malloc" (and not to "debug").
Add an unit test.
* _PyPreConfig_Read() now sets temporarily LC_CTYPE to the user
preferred locale, as _PyPreConfig_Write() will do permanentely.
* Fix _PyCoreConfig_Clear(): clear run_xxx attributes
* _Py_SetArgcArgv() doesn't have to be exported
* _PyCoreConfig_SetGlobalConfig() no longer applies preconfig
* _PyPreConfig_Write() now reallocates the pre-configuration with the
new memory allocator.
* It is no longer needed to force the "default raw memory allocator"
to clear pre-configuration and core configuration. Simplify the
code.
* _PyPreConfig_Write() now does nothing if called after
Py_Initialize(): no longer check if the allocator is the same.
* Remove _PyMem_GetDebugAllocatorsName(): dev mode sets again
allocator to "debug".
* _PyPreConfig_Write() now sets the memory allocator.
* _PyPreConfig_Write() gets a return type: _PyInitError.
* _Py_InitializeCore() now reads and writes the pre-configuration
(set the memory allocator, configure the locale) before reading and
writing the core configuration.
The development mode now uses the effective name of the debug memory
allocator ("pymalloc_debug" or "malloc_debug"). So the name doesn't
change after setting the memory allocator.
* Move 'allocator' and 'dev_mode' fields from _PyCoreConfig
to _PyPreConfig.
* Fix InitConfigTests of test_embed: dev_mode sets allocator to
"debug", add a new tests for env vars with dev mode enabled.
* Move following fields from _PyCoreConfig to _PyPreConfig:
* coerce_c_locale
* coerce_c_locale_warn
* legacy_windows_stdio
* utf8_mode
* _PyPreConfig_ReadFromArgv() is now responsible to choose the
filesystem encoding
* _PyPreConfig_Write() now sets the LC_CTYPE locale
* Add _PyPreConfig structure
* Move 'ignored' and 'use_environment' fields from _PyCoreConfig
to _PyPreConfig
* Add a new "_PyPreConfig preconfig;" field to _PyCoreConfig