Ruby » Ruby master

rdoc: --extension option fix

• lib/rdoc/parser.rb (RDoc.alias_extension): a real file is irrelevant
  to aliasing. [ruby-core:44796][Bug #6392]
• lib/rdoc/parser.rb (RDoc.zip?): non-existent file will not be a zip
  file.
• lib/rdoc/parser.rb (RDoc.can_parse_by_name): accept aliased
  extension file names.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@35532 b2dd03c8-39d4-4d8f-98ff-823fe69b080e