[tlbuild] Building asy - lots of new library deps

[Karl Berry]

    > - libcurl
    > - eigen: libeigen3
    open - should we enable that?

If merely a matter of installing a package, and if they can be linked
statically, then why not. But linking statically is probably not
easy. You probably know better than me how "portable" dynamic linking of
these (and tirpc) would be across distros.

Wdyt?

If a given library is not packaged for a given system, I wouldn't worry
about it.

    > - XDR/V3D support: libtirpc ...
    yes, we should enable according to build page.

I just wrote that in after Johannes' message. But now I realize the
extra shared lib might make it better to skip. --thanks, karl.