Support IELR(1) Parser Generation

[junk0612]

Support the generation of the IELR(1) parser described in this paper.
https://www.sciencedirect.com/science/article/pii/S0167642309001191

This PR will be ready for merging when the following is done.

• Add tests
  • Currently, I have only created a grammar file and verified its operation in my local environment.
• Refactor
  • The data structure is awful and needs to be improved because the priority was to achieve the expected results.

[jasone]

A couple months ago I poked around the internet looking for independent IELR(1) implementations, and besides lrama found only an inactive rust-based attempt. Recently I completed my own implementation and wrote a technical report with the hope that it might help others. IELR(1) turns out to be a real bear to figure out, even if it takes only a moderate amount of code. I hope you find the time and inspiration to complete this effort. Good luck!

[junk0612]

On 7da9676 , Lrama can parse CRuby's parse.y at ruby/ruby@028958f .

These are the files of parsing results.
ruby path/to/id2token path/to/parse.y | bundle exec lrama -v - lalr
lalr.output

ruby path/to/id2token path/to/parse.y | bundle exec lrama -D lr.type=ielr -v - ielr
ielr.output