now register both filenames in the exception on failure.
This required adding new C API functions allowing OSError exceptions
to reference two filenames instead of one.
_PyUnicode_CompareWithId() is faster than PyUnicode_CompareWithASCIIString()
when both strings are equal and interned.
Add also _PyId_builtins identifier for "builtins" common string.
instead of creating temporary Unicode string objects
Add also more identifiers in pythonrun.c to avoid temporary Unicode string
objets for the interactive interpreter.
* Catch PyFile_WriteString() and PyFile_WriteObject() errors
* Clear the current exception on _PyObject_GetAttrId() failure
* Use PyUnicode_CompareWithASCIIString() and PyFile_WriteObject() instead of
_PyUnicode_AsString() and strcmp() to avoid Unicode encoding error. stderr
has a more tolerant error handler than utf-8/strict.
with an assertion error if they are called with an exception set
(PyErr_Occurred()).
If these functions are called with an exception set, the exception may be
cleared and so the caller looses its exception.
Add also assertions to PyEval_CallObjectWithKeywords() and call_function() to
check if the function succeed with no exception set, or the function failed
with an exception set.
Forgot to raise ModuleNotFoundError when None is found in sys.modules.
This led to introducing the C function PyErr_SetImportErrorSubclass()
to make setting ModuleNotFoundError easier.
Also updated the reference docs to mention ModuleNotFoundError
appropriately. Updated the docs for ModuleNotFoundError to mention the
None in sys.modules case.
Lastly, it was noticed that PyErr_SetImportError() was not setting an
exception when returning None in one case. That issue is now fixed.
