* Credit myself and others.
* Complete asyncio changes.

This code was for deoptimization, which is removed from
PR-12884.

This patch implements per opcode cache mechanism, and use it in
only LOAD_GLOBAL opcode.

Based on Yury's opcache3.patch in bpo-26219.

Modify test_coroutines, test_cprofile, test_generators, test_raise,
test_ssl and test_yield_from to use
support.catch_unraisable_exception() rather than
support.captured_stderr().

test_thread: remove test_save_exception_state_on_error() which is now
updated. test_unraisable_exception() checks that sys.unraisablehook()
is called to handle _thread.start_new_thread() exception.

test_cprofile now rely on unittest for test discovery: replace
support.run_unittest() with unittest.main().

Apologies for the earlier hasty attempt.

test_coroutines: test_unawaited_warning_when_module_broken() now uses
support.check_warnings() to catch expected RuntimeWarning.

The main slot assignment loop is now if-else if ladder, making the
control flow clearer.

Based on suggestion by Victor Stinner in:
https://github.com/python/cpython/pull/10304/#issuecomment-491123026

https://bugs.python.org/issue35621

When inheriting a heap subclass from a vectorcall class that sets
`.tp_call=PyVectorcall_Call` (as recommended in PEP 590), the subclass does
not inherit `_Py_TPFLAGS_HAVE_VECTORCALL`, and thus `PyVectorcall_Call` does
not work for it.

This attempts to solve the issue by:
* always inheriting `tp_vectorcall_offset` unless `tp_call` is overridden
  in the subclass
* inheriting _Py_TPFLAGS_HAVE_VECTORCALL for static types, unless `tp_call`
  is overridden
* making `PyVectorcall_Call` ignore `_Py_TPFLAGS_HAVE_VECTORCALL`

This means it'll be ever more important to only call `PyVectorcall_Call`
on classes that support vectorcall. In `PyVectorcall_Call`'s intended role
as `tp_call` filler, that's not a problem.

* bpo-19184: Update the documentation of dis module

* Explain the behavior of the number of arguments of RAISE_VARGARGS
  opcode.

* bpo-19184: Update blurb.

* bpo-19184: Fix typo in the dis Documentation.

* bpo-19184: Address review comments and improve the doc

* bpo-19184: Remove news file.

As the code paths for various METH_* conventions are diverging due
to optimizations, we should check they continue to be covered by
GDB integration.

* bpo-37014: Update docstring and Documentation of fileinput.FileInput()

* Explain the behavior of fileinput.FileInput() when reading stdin.

* Update blurb.

* bpo-37014: Fix typo in the docstring and documentation.

Changes in bpo- 31858 made the less informative 'context_use_ps1' redundant.

bpo-35621: Support running subprocesses in asyncio when loop is executed in non-main thread (#13630)