PyFrame_GetCode(frame): return a borrowed reference to the frame
code.
Replace frame->f_code with PyFrame_GetCode(frame) in most code,
except in frameobject.c, genobject.c and ceval.c.
Also add PyFrame_GetLineNumber() to the limited C API.
* sys.settrace(), sys.setprofile() and _lsprof.Profiler.enable() now
properly report PySys_Audit() error if "sys.setprofile" or
"sys.settrace" audit event is denied.
* Add _PyEval_SetProfile() and _PyEval_SetTrace() function: similar
to PyEval_SetProfile() and PyEval_SetTrace() but take a tstate
parameter and return -1 on error.
* Add _PyObject_FastCallTstate() function.
Fix invalid function cast warnings with gcc 8
for method conventions different from METH_NOARGS, METH_O and
METH_VARARGS excluding Argument Clinic generated code.
PyStructSequence_InitType() except that it has a return value (0 on success,
-1 on error).
* PyStructSequence_InitType2() now raises MemoryError on memory allocation failure
* Fix also some calls to PyDict_SetItemString(): handle error
module name anymore, only work on unicode strings. Therefore it doesn't
truncate module names with embedded NUL characters, or fail if the module name
contains surrogate characters (UTF-8 encoder fails on a surrogate character).
Patch written by Alexander Belopolsky.
