gmp-6.1.0 fat build crashes on Broadwell / Cygwin 64bit

[Torbjörn Granlund]

ASSI <Stromeko at nexgo.de> writes:

  I have confirmation from two people who've reported the problem originally 
  that the gmp built with this patch is working for them when they do the same 
  things that previously would crash their programs.
  
Thanks for the feedback.

(This shows a flaw in our testing which we will need to address.)

-- 
Torbjörn
Please encrypt, key id 0xC8601622