parse.y: intern_cstr

* parse.y (intern_cstr): remove `_without_pindown` suffix and use
  rb_intern3() as well as RIPPER, for the time being.
  [ruby-core:65009] [Bug #10206]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@47569 b2dd03c8-39d4-4d8f-98ff-823fe69b080e