Changes:
* Split _PySys_SetArgvWithError() into subfunctions for Py_Main():
* Create the Python list object
* Set sys.argv to the list
* Compute argv0
* Prepend argv0 to sys.path
* Add _PyPathConfig_ComputeArgv0()
* Remove _PySys_SetArgvWithError()
* Py_Main() now splits the code to compute sys.argv/path0 and the
code to update the sys module: add pymain_compute_argv()
subfunction.
_PyPathConfig_Init() now also initialize home and program_name:
* Rename existing _PyPathConfig_Init() to _PyPathConfig_Calculate().
Add a new _PyPathConfig_Init() function in pathconfig.c which
handles the _Py_path_config variable and call
_PyPathConfig_Calculate().
* Add home and program_name fields to _PyPathConfig.home
* _PyPathConfig_Init() now initialize home and program_name
from main_config
* Py_SetProgramName(), Py_SetPythonHome() and Py_GetPythonHome() now
calls Py_FatalError() on failure, instead of silently ignoring
failures.
* config_init_home() now gets directly _Py_path_config.home to only
get the value set by Py_SetPythonHome(), or NULL if
Py_SetPythonHome() was not called.
* config_get_program_name() now gets directly
_Py_path_config.program_name to only get the value set by
Py_SetProgramName(), or NULL if Py_SetProgramName() was not called.
* pymain_init_python() doesn't call Py_SetProgramName() anymore,
_PyPathConfig_Init() now always sets the program name
* Call _PyMainInterpreterConfig_Read() in
pymain_parse_cmdline_envvars_impl() to control the memory allocator
* C API documentation: it's no more safe to call Py_GetProgramName()
before Py_Initialize().
* Factorize code from PC/getpathp.c and Modules/getpath.c to remove
duplicated code
* rename pathconfig_clear() to _PyPathConfig_Clear()
* Inline _PyPathConfig_Fini() in pymain_impl() and then remove it,
since it's a oneliner