doc/extension.rdoc: update paths for defs/ directory
These files were moved in r19844
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@53880 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
doc/extension.rdoc: update paths for defs/ directory
These files were moved in r19844
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@53880 b2dd03c8-39d4-4d8f-98ff-823fe69b080e