yle-dl: install AdobeHDS.php when HEAD.

See https://github.com/aajanki/yle-dl#installation . Note that due to an
upstream bug, the installation happens only for HEAD, for now.

Closes #35212.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>
tcc: add a test (hello world with `tcc -run`)
tcc: add 0.9.26 bottle.