Issue #20710: The pydoc summary line no longer displays the "self" parameter
for bound methods.  Previous to this change, it displayed "self" for methods
implemented in Python but not methods implemented in C; it is now both
internally consistent and consistent with inspect.Signature.
Issue #19748: On AIX, time.mktime() now raises an OverflowError for year
outsize range [1902; 2037].