Before, --color on would affect colored compile error printing but not
affect terminal progress bar printing. It was intended for this option
to affect both; now it does.

This causes a failure when building the language reference, which
contains code for parsing terminal output and rendering HTML. Now it
must be expanded to handle 'K' and 'D' codes to simulate a terminal
cursor moving, and the CI will fail until that capability is added in a
later commit of this branch.

I extracted this change from #13560 so that the idea is not lost but we
can solve this issue separately.