gmp 5.1.1 tests failures on 64 bin windows with AMD processors

[Torbjorn Granlund]

Darin Ohashi <dohashi at maplesoft.com> writes:

  I've attached the output from configure, config.log and config.m4.
  
Thanks.

  My first thought about this bug was that it was related to the cpu id
  code used for the fat binaries.  Is there anyway to force gmp to use a
  particular hardware optimized version, an environment variable perhaps?
  Is there a way to see what gmp's cpu id code thinks the current hardware
  is?
  
One can edit WANT_FAKE_CPUID in mpn/x86-64/fat/fat.c to enable 'fake'
cpuid.  Then the envvar GMP_CPU_TYPE controls the cpu type choice, where
valid values are in a table in the same file.

There is no way to see what GMP chooses under normal build.  (Under
WANT_FAKE_CPUID = 1, one either gets ones way or an error message.)

I am at least now able to reproduce the reported problem using the FAKE
echanism.

-- 
Torbjörn