[3.8] bpo-38410: Properly handle PySys_Audit() failures

[serhiy-storchaka]

_PyEval_SetAsyncGenFinalizer() and _PyEval_SetAsyncGenFirstiter()
didn't include proper error handling for their PySys_Audit() calls.

Co-authored-by: Zackery Spytz zspytz@gmail.com

https://bugs.python.org/issue38410

[codecov]

Codecov Report

Merging #18658 into 3.8 will increase coverage by 2.96%.
The diff coverage is n/a.

@@             Coverage Diff             @@
##              3.8   #18658       +/-   ##
===========================================
+ Coverage   79.13%   82.10%    +2.96%     
===========================================
  Files         381     1918     +1537     
  Lines      172572   576877   +404305     
  Branches        0    43736    +43736     
===========================================
+ Hits       136562   473624   +337062     
- Misses      36010    93684    +57674     
- Partials        0     9569     +9569     

Impacted Files	Coverage Δ
Modules/_decimal/libmpdec/umodarith.h	80.76% <0.00%> (-19.24%)	⬇️
Modules/clinic/spwdmodule.c.h	58.33% <0.00%> (-3.21%)	⬇️
Modules/clinic/resource.c.h	78.57% <0.00%> (-2.68%)	⬇️
Modules/clinic/_pickle.c.h	62.40% <0.00%> (-2.33%)	⬇️
Modules/clinic/signalmodule.c.h	71.51% <0.00%> (-2.32%)	⬇️
Python/clinic/marshal.c.h	77.77% <0.00%> (-2.23%)	⬇️
Modules/clinic/_weakref.c.h	77.77% <0.00%> (-2.23%)	⬇️
Modules/clinic/_queuemodule.c.h	78.08% <0.00%> (-2.17%)	⬇️
Modules/_multiprocessing/clinic/posixshmem.c.h	66.66% <0.00%> (-2.09%)	⬇️
Objects/clinic/moduleobject.c.h	78.94% <0.00%> (-2.01%)	⬇️
... and 1804 more

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