Issue #27938: Normalize aliases of the ASCII encoding, because
_Py_normalize_encoding() now correctly normalize encoding names.

HOME is not set on Windows for example.

Use also textwrap.dedent() for the script.

Patch by Martin Matusiak and Sam Kimbrel.

Issue #28056 and issue #26058.

by the user.

It turns out we can't depend on email.message getting imported every place
message_factory is needed, so to avoid a circular import we need to special
case Policy.message_factory=None in the parser instead of using monkey
patching.  I had a feeling that was a bad idea when I did it.

generalizations added in 3.5.

Issue #27810:

* Modify vgetargskeywordsfast() to work on a C array of PyObject* rather than
  working on a tuple directly.
* Add _PyArg_ParseStack()
* Argument Clinic now emits code using the new METH_FASTCALL calling convention

Issue #27810: Add a new calling convention for C functions:

    PyObject* func(PyObject *self, PyObject **args,
                   Py_ssize_t nargs, PyObject *kwnames);

Where args is a C array of positional arguments followed by values of keyword
arguments. nargs is the number of positional arguments, kwnames are keys of
keyword arguments. kwnames can be NULL.

Issue #28040: Fix _PyDict_DelItem_KnownHash() and _PyDict_Pop(): convert
splitted table to combined table to be able to delete the item.

Write an unit test for the issue.

Patch by INADA Naoki.

Patch by Jason Fried.

Issue 27948: Allow backslashes in the literal string portion of f-strings, but not in the expressions. Also, require expressions to begin and end with literal curly braces.

Why do we have two sysconfig modules again?

generalizations added in 3.5.