[NNUE] Worker update on fishtest

[Joost VandeVondele]

To prepare fishtest for the testing of the NNUE evaluation, a worker update on fishtest was necessary and has been implemented. In most cases, this update should be automatic.

Two changes could affect contributors:

* custom_make.txt has been removed, to allow for a more appropriate architecture selection. If your use of custom_make.txt was essentially equivalent to

make ARCH=x86-64-bmi2 profile-build

this will now be done automatically. Exotic use cases are right now not supported, if you have one of those please file an issue (https://github.com/glinscott/fishtest/issues)

* NNUE requires the compiler (g++) to be sufficiently recent and to support c++17. At least gcc 7.5.0 is needed, more recent recommended.

If any issues appear with the worker update process, reply to this thread or preferably file an issue at https://github.com/glinscott/fishtest/issues

[Alexandre Meirelles]

Nice. When the NNs will start to be produced?

Cheers!

[Cscuile]

Awesome! Look forward to seeing NNUE tests. I'd highly recommend someone submit Elo tests with 2138 Sergio. That network seems to be one of the strongest so far.