Help stabilising mini-gmp

[Torbjörn Granlund]

I created a web page for tracking the mini-gmp problems:

  https://gmplib.org/devel/mini-gmp-status.html

I'd like to stress that mini-gmp problems do not affect the quality of
GMP itself.  GMP uses mini-gmp for some bootstrapping tasks, but that's
known to work properly for both 32-bit and 64-bit machines.

For comitters:

For those issues which result in a check/failure entry, I have marked
them as "expected" (by means of ~gmp/gmp/expected_check_failures).  I
did that to make sure these failures do not hide any problems with GMP
itself.

If you check in a fix for any of these problems, please strike the
entire item by using <del>...</del>.  Please also clean up the
~gmp/gmp/check/failure report files.

-- 
Torbjörn
Please encrypt, key id 0xC8601622