add noarch build variant for native packages

[proppy]

As discussed with @mithro and @hzeller, it could be interesting to have noarch build variant of some of the packages for native cli tool like yosys, magic, openroad, netgen, xls; so that they can easily be installed on multiple platform.

(This is likely to be more challenging for graphical package or python package with native extension)

possible implementation:

• https://github.com/jart/cosmopolitan
• wasm similar to what's done with http://yowasp.org/

curious what others think?

[mithro]

Great in theory, much harder to do in practice. I don't think we have the bandwidth to support yet another build flow?

[mithro]

YoWASP might be a better / easier solution in the short term?