Advanced Buildbot Hackery

Folks,

I'm trying to create a buildbot that would do a great many things,
including building clang/llvm/compiler-rt + check-all and
libc++/libc++abi + testit, install all that into a prefix and run the
test-suite with it.

I know ClangBuilder can pull compiler-rt with it, and make check-all
would also include its tests. I also know that there is a
LibCXXBuilder that can build and test libc++, and that there is an
LNTBuilder that can run the test-suite, but I don't know if it's
possible to join them all together in one buildbot to rule them all
kind of way.

Since we have many other buildbots (fast and slow ones), this one
could actually take a long time to run (like a day), it doesn't matter
that much. But would be good to have a confirmation that the whole
toolchain is working in unison for a particular architecture.

In the future, I'd like to add an LLD build integrated with this
mega-bot, to close the lid on the LLVM Toolchain package.

Has it been done? If not, is it possible?

cheers,
--renato