mini-gmp mpz_{get,set}_d not fully compatible with GMP

[Torbjörn Granlund]

Marc Glisse <marc.glisse at inria.fr> writes:

  It is also possible to determine it at runtime (comparing 2^n+{0,1,2}
  for instance should work whether we round up, down or to the nearest;
  tests/misc.c compares 2^n+1-2^n to 1, which also looks good), doing it
  once and storing the result somewhere.

Oops, sorry for repeating your suggestion.

-- 
Torbjörn
Please encrypt, key id 0xC8601622