[rubygems/rubygems] More compact open_file fallback on Windows

https://github.com/rubygems/rubygems/commit/8f34396af6

lib/rubygems.rb

@@ -807,9 +807,7 @@ An Array (#{env.inspect}) was passed in from #{caller[3]}
     if Thread.main != Thread.current
       raise
     else
-      File.open(path, flags) do |io|
+      File.open(path, flags, &block)
-        yield io
-      end
     end
   end