* Sync YARP gemspec
We were previously not syncing the YARP gemspec over which meant
that the Ruby YARP gem was out of sync.
* Sync YARP node / lex_compat files
This commit is the initial sync of all files from ruby/yarp
into ruby/ruby. Notably, it does the following:
* Sync all ruby/yarp/lib/ files to ruby/ruby/lib/yarp
* Sync all ruby/yarp/src/ files to ruby/ruby/yarp/
* Sync all ruby/yarp/test/ files to ruby/ruby/test/yarp