(https://github.com/ruby/rdoc/pull/1144)

* Add a new ruby parser RDoc::Parser::PrismRuby

* Add a new ruby parser testcase independent from parser's internal implementation

* unknown meta method

* Use MethodSignatureVisitor only to scan params, block_params and calls_super

* Add calls_super test

* Drop ruby 2.6. Prism requires ruby >= 2.7

* Remove duplicated documentation comment from prism_ruby.rb

* Add test for wrong argument passed to metaprogramming method

* Rename visit_call_[DSL_METHOD_NAME] to make it distinguishable from visit_[NODE_TYPE]_node

* Method receiver switch of true/false/nil to a case statement

* Extract common part of add_method(by def keyword) and add meta_comment method

* Reuse consecutive comments array when collecting comments

* Simplify DSL call_node handling

* Refactor extracting method visibility arguments

https://github.com/ruby/rdoc/commit/fde99f1be6