* master: (104 commits)
  Fast path for exact floats in math.hypot() and math.dist() (pythonGH-8949)
  Remove AIX workaround test_subprocess (pythonGH-8939)
  bpo-34503: Fix refleak in PyErr_SetObject() (pythonGH-8934)
  closes bpo-34504: Remove the useless NULL check in PySequence_Check(). (pythonGH-8935)
  closes bpo-34501: PyType_FromSpecWithBases: Check spec->name before dereferencing it. (pythonGH-8930)
  closes bpo-34502: Remove a note about utf8_mode from sys.exit() docs. (pythonGH-8928)
  Remove unneeded PyErr_Clear() in _winapi_SetNamedPipeHandleState_impl() (pythonGH-8281)
  Fix markup in stdtypes documentation (pythonGH-8905)
  bpo-34395: Don't free allocated memory on realloc fail in load_mark() in _pickle.c. (pythonGH-8788)
  Fix upsizing of marks stack in pickle module. (pythonGH-8860)
  bpo-34171: Prevent creating Lib/trace.cover when run the trace module. (pythonGH-8841)
  closes bpo-34493: Objects/genobject.c: Add missing NULL check to compute_cr_origin() (pythonGH-8911)
  Fixed typo with asynccontextmanager code example (pythonGH-8845)
  bpo-34426: fix typo (__lltrace__ -> __ltrace__) (pythonGH-8822)
  bpo-13312: Avoid int underflow in time year. (pythonGH-8912)
  bpo-34492: Python/coreconfig.c: Fix _Py_wstrlist_copy() (pythonGH-8910)
  bpo-34448: Improve output of usable wchar_t check (pythonGH-8846)
  closes bpo-34471: _datetime: Add missing NULL check to tzinfo_from_isoformat_results. (pythonGH-8869)
  bpo-6700: Fix inspect.getsourcelines for module level frames/tracebacks (pythonGH-8864)
  Fix typo in the dataclasses's doc (pythonGH-8896)
  ...