Use libexec for distination directory.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@65978 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

tool/sync_default_gems.rb

@@ -88,7 +88,7 @@ def sync_default_gems(gem)
   when "bundler"
     `rm -rf lib/bundler* libexec/bundler libexec/bundle libexec/bundle_ruby spec/bundler man/bundle* man/gemfile*`
     `cp -r ../../bundler/bundler/lib/bundler* ./lib`
-    `cp -r ../../bundler/bundler/exe/bundle* ./bin`
+    `cp -r ../../bundler/bundler/exe/bundle* ./libexec`
     `cp ../../bundler/bundler/bundler.gemspec ./lib`
     `cp -r ../../bundler/bundler/spec spec/bundler`
     `cp -r ../../bundler/bundler/man/*.{1,5,1\.txt,5\.txt,ronn} ./man`