* Fix a temp leak in the type init code.
* Fix temp leaks in fused types initialisation code.
* Correctly release the buffer index temps allocated for index calculations.
* Make tests fails hard if a temp variable is not released at the end of a generated function.
* Fix temp leak in switch statement code.
* Make end-to-end tests fail on refnanny output.
* Fix result temp leak in PyTypeTestNode.
* Fix result temp leak in external type/function import code and enable the refnanny check for them.
* Fix temp leak when try-return-finally is used in generators.
* Make it explicit when an allocated temp is not meant to be reused.
* Fix temp leak when assigning to the real/imag attributes of complex numbers.
* Fix temp leak when assigning to a memoryview slice.
* Clean up "num_threads" result temp in parallel section, not only in prange loop.
* Fix temp leak in Pythran buffer setitem code.
* Simplify NumPyMethodCallNode since it does not need the Python function anymore. Previously, it generated code that needlessly looked up the Python function without actually using it.
* Fix temp leak when deleting C++ objects.
* Add a test that actually reusing temps when deleting C++ objects works correctly.

`PyModule_GetDict` is part of the limited API so we can keep a reference
to the module dict around regardless of limited mode being enabled or not.

Avoid a call to PyTuple_GET_ITEM() to get the item array pointer if CYTHON_ASSUME_SAFE_MACROS is disabled.
See https://github.com/cython/cython/issues/3701

exec() did not allow recent Python syntax features in Py3.8+ due to https://bugs.python.org/issue35975
Closes https://github.com/cython/cython/issues/3695

Closes #1603.

Rebased 1bb26b96 for cython 0.29.x,
and made conditional to Python 3.  This does not solve the original staticmethod problem
in Python 2 but it does resolve classmethod problems in Python 3.9.  Therefore, it unbreaks
other packages on Python 3.9, improves overall state for Python 3 and does not introduce
regressions in Python 2.

This is a backwards incompatible change that enables Python semantics for special methods by default, while the directive allows users to opt out of it and go back to the previous C-ish Cython semantics.

See https://github.com/cython/cython/issues/2056

Re-add "c_api_binop_methods" directive for backwards compatibility after reverting https://github.com/cython/cython/pull/3633 and force it to "False".
Closes #3688.

This reverts commit e6a81240.

This reverts commit d849fb23.

This reverts commit bcb93877.

This reverts commit 02bb311d.

This reverts commit 66773260.