[Patches] introducing math.rint

[Tim Peters]

[Guido van Rossum]
> I've checked this in, but I have one nagging doubt: it's not a
> standard ANSI C function, so may not exist on all platforms?

Legitimate concern -- rint is one of many functions recommended by the
IEEE-754 std that aren't in ISO/ANSI C.  Most platforms support all of those
one way or another now, but usually via platform-specific spellings.  This
won't improve until C9X is adopted.  IIRC (& I have no way to check this
right now), rint is not supported under EPOC32 (the Symbian/Psion OS that
Duncan Booth did a port for).  To be safe, afraid this really needs
conditional config support.