Benchmarks for ANTLR and funcparselib

[erezsh]

As discussed in lark-parser/lark#487, code is here: https://gist.github.com/erezsh/c2b51a03273f2485317fc83e75fa162c

[erezsh]

P.S. the antlr code expects an older version (it will tell you which one), but seems to work with the newest one as well.

[goodmami]

Great, thanks. And I think making a gist was a great idea, so there's a record of the original code.