Embedding Blink builds in Cosmo executables was a failed experiment. It
turned out to be easier than expected to let the mono repo have support
for multiple architectures. Blink still works great; it's supported and
recommended; just please use it as a separate program. For example, you
can use Blink to run Cosmo binaries on architectures like i486 / s390x.
Somehow or another, I previously had missed `BUILD.mk` files.
In the process I found a few straggler cases where the modeline was
different from the file, including one very involved manual fix where a
file had been treated like it was ts=2 and ts=8 on separate occasions.
The commit history in the PR shows the gory details; the BUILD.mk was
automated, everything else was mostly manual.
