6.2.0 always uses BMI1/2 instructions

[Torbjörn Granlund]

GMP will include instructions for the host for which GMP is configured,
These instructions come from asm file which GMP's configure selects, and
from compiler generated code which results from compiler command line
options which GMP passes.

If you want GMP to run on older machines, configuring it for some very
ld machine might work, or more robustly configuring it for a generic
architecture such as x86_64.

But GMP supports fat binaried from x86 and x86_64, and that is probably
the best choice.  Please see the GMP manual for details.

-- 
Torbjörn
Please encrypt, key id 0xC8601622