Open issues (TODO list):
- review and apply listpop.patch and frame_fasttolocals.patch
- fix CJK codecs: using UNIINV to report _PyUnicodeWriter_WriteChar() failure in Modules/cjkcodecs/cjkcodecs.h does not work. The caller is not aware of the failure: multibytecodec_decerror() receives e=1, whereas it should get MBERR_EXCEPTION
- fix Modules/pyexpat.c: handlers do no detect failures
- fix sqlite: Modules/_sqlite/connection.c calls the finalize method on the aggregate whereas calling step() failed
- fix tests hang when an exception occurs in a thread
- fix new bugs found by pyfailmalloc :-)