clang compatibility fixes

[mieko]

The default value in the mkLit declaration (vs. definition) won't compile with modern clang. The other minor edits are warning fixes. This version of minisat is still current with upstream, but minisat PRs with a fix haven't gotten a response in a while.

Ref: niklasso/minisat#16, niklasso/minisat#22, niklasso/minisat#12, niklasso/minisat#27. Closes #1

[mieko]

@mame said in #1:

This issue should be fixed in the upstream of minisat. I have no thought of patching the bundled source of minisat.

This really should be fixed upstream, although there has been little response. I understand not wanting to carry around a patched copy, so I'll leave this branch around for anyone who needs it, assuming the PR is closed.

[alexrudall]

mieko - thank you for leaving the branch, I have been able to use it successfully on OSX with the following in my Gemfile:

gem 'ruby-minisat', git: 'https://github.com/mieko/ruby-minisat', branch: 'clang-fixes'

Much appreciated!

[mame]

Sorry for my long absence. It is really unfortunate that minisat is not maintained. Now it fails to build on my machine 😢 , so I'll merge it. Thank you very much.

[mieko]

@mame I just appreciate you putting it together. Thanks so much.