Squashed 'gen/' content from commit 5a46e03

git-subtree-dir: gen
git-subtree-split: 5a46e03b308dc0f30da2017b9fa6e3be7130b1eb
Merge commit '4793a6acde617eca782e3de2a6652b0d6e1d6cf3' as 'gen'
use subtree gen/ for CCGen (symlink)
Merge PR from drup with gen/ subtree