Cleanup fiddle extenstion when sync them from github repo.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@65209 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

tool/sync_default_gems.rb

@@ -122,6 +122,7 @@ def sync_default_gems(gem)
     `cp -rf ../fiddle/test/fiddle test`
     `cp -f ../fiddle/fiddle.gemspec ext/fiddle`
     `git checkout ext/fiddle/depend`
+    `rm -rf ext/fiddle/lib/fiddle.{bundle,so}`
   when "stringio"
     `rm -rf ext/stringio test/stringio`
     `cp -rf ../stringio/ext/stringio ext`