The GMP docs say:

    Counts of bits of a multi-precision number are represented in the C
    type mp_bitcnt_t. Currently this is always an unsigned long, but on
    some systems it will be an unsigned long long in the future.

Now that divModInteger isn't inlined, we were getting allocations for
both results even if we're just going to throw one away.

Recent change means ul is truncate to an int, not a long anymore.

rolling back:

Sat Nov 21 16:43:13 EST 2009  Ben.Lippmeier@anu.edu.au
  * Windows DLLs: Tag imported gmp symbols with the package they're from.

    M ./cbits/gmp-wrappers.cmm -20 +20

This works around a crash (only on OS X for some reason?) where the GHCi
GMP uses the systems memory allocator. We should fix this properly, by
making ghci run constructor functions.

Moved here from the rts.