Firefox 109 on POWER

Firefox 109 is out with new support for Manifest V3 extensions, but without the passive-aggressive deceitful crap Google was pushing (yet another reason not to use Chrome). There are also modest HTML, CSS and JS improvements.

As before linking still requires patching for bug 1775202 using this updated small change or the browser won't link on 64-bit Power ISA (alternatively put --disable-webrtc in your .mozconfig if you don't need WebRTC). Otherwise the browser builds and runs fine with the LTO-PGO patch for Firefox 108 and the .mozconfigs from Firefox 105.