Chromium on POWER9 ready to land

As reported on the Chromium development mailing list, patches are ready to land to make Chromium production-ready on the Talos II and other POWER9 systems. The last remaining blocker in libvpx was worked around by disabling VSX-AltiVec support, presumably temporarily (the patches TenFourFox uses for AltiVec VP8 and VP9 are maintained independently and are not part of libvpx). This includes a functional JavaScript JIT using V8.

Chromium is an important dependency for many tools, such as QtWebEngine, so this port definitely improves the T2's viability and compatibility as a workstation. However, I'll say as a personal note, and with full disclosure as a long-time member of the Mozilla community, moves like Chrome 69's forced integration with Google web services (even cookies won't be cleared unless you log out) continue to make me unwilling to support this project myself even though I'm glad it exists. At least there are alternatives like Ungoogled Chromium, at least for right now.

Firefox doesn't have a JIT, but it also doesn't have Google or its general untrustworthiness and it otherwise works fine, and my goal is to get ppc64le supported in SpiderMonkey eventually. Meanwhile, if you really do prefer Chromium, you now have a fully-working port and this hard work should be commended.