The giant patch was unnecessary, I misread what the struct module was
actually doing.  Auditing all uses of struct in the standard library the
only ones that look suspicious to me are:

Lib/posixfile.py
and all of the uses in Lib/plat-mac/

posixfile is probably fine, but it wouldn't surprise me if there are
bugs on some platforms in there due to using 'l' to decode off_t and 'h'
to decode pid_t within a fcntl structure.

The plat-mac stuff might break assuming those APIs are even available to
64bit programs.  I'll leave that up to the mac porting folks, as it is
its difficult if not impossible to even build a 64-bit Python under OS X.

Fixed in trunk r60234.