This patch does a few things:
1) Change all the in-tree tooltool manifests to contain sccache2 instead of the existing Python sccache
2) Change mozconfig.cache to point at sccache.
3) Lightly tweak the --with-cccache configure option to support sccache, and detect whether we're using ccache or sccache and set an option appropriately.
4) Add a MOZ_SCCACHE_VERBOSE_STATS option, and add a target in the top-level Makefile to make sccache spit out its stats at the end of the build. This is useful to see the cache hits/errors until we get something better.
5) Add MOZ_USING_SCCACHE to the build telemetry. Not that I think it will be immediately useful, but for future use.
MozReview-Commit-ID: 9lrdLwNj5Bm
--HG--
extra : rebase_source : d323457df10d0ee0ac5811940e518d9422a7e070