[Lightning] test environments for non-x86 CPUs

[Bruno Haible]

Hi,

The GNU lightning 2.1.1 release announcement [1] says
  "alpha, hppa, mips (n32 abi), ppc (Darwin abi) and sparc ports
   are no longer supported due to lack of a test environment."

For alpha, hppa, mips, sparc you can produce test environments using
qemu. You find my instructions at [2], based on those by Torbjörn
Granlund [3].

For Mac OS X/ppc, there are two ways:
  - Get access to a real Mac OS X 10.5 PowerPC hardware per ssh.
  - Get access to a real Mac OS X 10.5 x86_64 hardware per ssh, and
    use CC="gcc -arch ppc".

Let me know if you need more info. I am using these test environments
daily for GNU libffcall and GNU clisp.

Best regards,

           Bruno

[1] https://savannah.gnu.org/forum/forum.php?forum_id=8951
[2] 
http://git.savannah.gnu.org/gitweb/?p=libffcall.git;a=tree;f=porting-tools/emulation
[3] https://gmplib.org/~tege/qemu.html