Bug 1348134 https://bugzilla.mozilla.org/show_bug.cgi?id=1348134 delays source compression to GCs, but critically disables it completely on single CPU systems (see https://hg.mozilla.org/integration/mozilla-inbound/rev/c7955d6d0759, ::enqueueOffThreadSourceCompression()). We just shouldn't bother at all on any Power Mac, it's probably not worth it.
Bug 1348134 https://bugzilla.mozilla.org/show_bug.cgi?id=1348134 delays source compression to GCs, but critically disables it completely on single CPU systems (see https://hg.mozilla.org/integration/mozilla-inbound/rev/c7955d6d0759,
::enqueueOffThreadSourceCompression()). We just shouldn't bother at all on any Power Mac, it's probably not worth it.