(instead of a buffer of 2 GB)

Patch by Bryce Verdier.

This corresponds with change b9390aa12855 to PEP-11.

crc32() and adler32(). Patch written by Steffen Daode Nurpmeso.

doesn't have PY_SSIZE_T_CLEAN define and the size doesn't fit in an int (length
bigger than 2^31-1 bytes).

written if PY_SSIZE_T_CLEAN is defined.

to get around a mmap bug with sparse files. Patch written by Steffen Daode
Nurpmeso.

descriptor, the check of the object type doesn't read the __class__ attribute
anymore.  Fix a crash if a class override its __class__ attribute (e.g. a proxy
of the str type).

Patch by Lars Michelsen.