Linking failure on aarch64

[Torbjörn Granlund]

  > ./configure --build=aarch64-apple-darwin MPN_PATH=generic

  Does it work better if you use the documented --disable-assembly instead?
  (disabling assembly seems like a strange thing to do...)

For a new platform, disabling GMP's assembly actually makes some sense.

Apple uses the archaic convention of prepending an underscrore to glocal
symbols.  GMP handles that for really ancient BSD systems as well as for
Macos on Powerpc and x86.  But GMP does not handle that for Macos on
Arm.

-- 
Torbjörn
Please encrypt, key id 0xC8601622