Closes https://github.com/cython/cython/issues/4214
Closes https://github.com/cython/cython/issues/2811

* Set "entry.qualified_name" for builtin types.
* Make sure we always have a correct "qualified_name" for all symtab Entry instances.

ALways mark the entry of generator expression functions as used. Because, why not, they probably are. And it avoids false warnings.
Fixes https://github.com/cython/cython/issues/1699

Don't access directly PyObject.ob_type and PyObject.ob_refcnt members.

Do not install Pythran in 0.29.x on travis since it is currently incompatible and unknown when it will work again.

Implement "gen.gi_frame" and "coro.cr_frame" attributes on generators and coroutines that return an inspectable (although otherwise dead) frame object.

Closes https://github.com/cython/cython/issues/2306

The utility code was generated at too late a stage, after the utility code from the pxd was merged into the pyx scope.

Fixes #1415

* Use the same fallback as for missing PEP-393 support.
* Prepare for "PyUnicode_READY()" and "PyUnicode_WCHAR_KIND" to be removed in Py3.12.
  See https://www.python.org/dev/peps/pep-0623/
* Avoid C compiler warnings about deprecated C-API functions in Py3.9+.

Closes https://github.com/cython/cython/issues/3925

Fix Python install script on appveyor: The URL path uses three digit Python versions, not just major.minor.

According to the docs, "/Od" is the default in MSVC, so in order to get it, it should be enough to clear CFLAGS.
Setting it generates warnings in Py3.9 on appveyor ("source file '"/Od"' ignored"), suggesting that the option is not recognised as such.
https://docs.microsoft.com/en-us/cpp/build/reference/od-disable-debug?view=msvc-160

Remove "PYTHONHOME" setting from embed-test since it seems to break the I/O encoding setup in (at least) Py3.8+ venvs.

Signed-off-by: Andrew V. Jones <andrew.jones@vector.com>

Closes https://github.com/cython/cython/pull/4101
See https://github.com/cython/cython/issues/4100

* Handle constant folding for LanguageLevel 2 on Python 3. Ensure that when StrNode is a BytesLiteral, that we don't coerce it to unicode.
* Add test for string multiplication bug. Needed to change the TreePath slightly to allow bytes-to-str comparison.

Fixes https://github.com/cython/cython/issues/3951

Remove incorrect dict unpacking optimisation that leaked external dict changes into the result (GH-4091)

Closes https://github.com/cython/cython/issues/3227

Creating global CDEFS for holding compiler definitions. Then pass it to the distutils.

Also add .vscode folder to .gitignore

Fixes https://github.com/cython/cython/issues/4096

Fix optimised_pow2_inplace() doctest on Python 3.10 because the error message changed.

Python 3.9 error message:
    unsupported operand type(s) for ** or pow(): 'int' and 'str'

Python 3.10 error message:
    unsupported operand type(s) for **=: 'int' and 'str'

Re-disable third-party integration testing in Py2.6 entirely since most packages aren't compatible anymore (and I don't want to dig up the versions that are).

Freeze the test dependency packages for Python 2.x to prevent further deprecations. More and more packages drop Py2 support these days.

See https://github.com/cython/cython/issues/3919

The loop parameter of asyncio.sleep(), deprecated in Python 3.8, has
been removed in Python 3.10. asyncio.sleep() gets implicitly the loop
in Python 3.10 and it is safe to do the same on Python 3.6:
https://docs.python.org/dev/whatsnew/3.10.html#changes-in-the-python-api

Backport code from the master branch:

* commit 4e785d42
* commit a9fb7768