This allows us to always unpack our builds into upstream/ or fastcomp/, instead of creating a new directory each time. Since without this, we'd get told to download a new file, and the emsdk would see that where it would be unpacked had contents, and assumed that even though it wasn't downloaded it must be the same. So we'd silently skip it.
It's useful to always unpack into the same dir since it's easier for people that create their own .emscripten file (the location of emscripten etc. is all fixed under the emsdk), and also it avoids directories accumulating, which each take hundreds of megabytes, so over time it can get burdensome.
We can remove this now that we have emscripten-releases working and use it everywhere we used the emsdk's waterfall integration.
In particular this should fix the current lkgr.json errors people are seeing (by removing all the lkgr stuff), which I believe started when I refactored that code while doing the releases work - I must have gotten something wrong on non-linux OSes. But anyhow, easier to remove that unnecessary code than fix it at this point.
* Structures emscripten-releases-tags.txt to mention the latest release, and then a list of all previous releases.
* Adds a new release for 1.38.33.
* If the manifest has emscripten_releases_hash, then we write out emscripten-version.txt with the proper version. We start with the hash, and check if there is a released version for it, if so we emit that, otherwise we emit the hash.
* Windows zipfile fix.
Updated to our current initial plan here:
* Add emscripten-releases-tags.txt which is a JSON file with a map of tag name to git hash in the emscripten-releases repo. Right now this file is just checked in here; in the future we may make the emsdk update it from git tags with update-tags etc.
* That file contains a "latest" tag, which is fetched for when getting latest-releases-[upstream|fastcomp]. We may want that to eventually be updated based on the latest green stuff on the bots perhaps.
* Rename the current sdk-[upstream|fastcomp]-* etc. to sdk-waterfall-[upstream\|fastcomp]-*. Then we'll have sdk-releases-[upstream|fastcomp]-* etc. This is just an internal name change - emsdk install latest-upstream still works as before, and still uses the waterfall (so we don't break our github CI).
* Add support for emsdk install latest-releases-[upstream\|fastcomp]
* Add a test using the actual emscripten-releases builds
Without this, we would not download new versions, as the filename looked the same ("already downloaded"). We'd unzip those old contents to a directory with the new name, giving the impression we updated when we didn't :(
(This was reverted by mistake. It had a bad commit message though, so relanding with a nicer one is nice anyhow.)
With this, we can do emsdk install latest-fastcomp and it installs fastcomp from the waterfall. That is, we then have 3 main sdks people might want to use:
* latest which installs fastcomp-llvm (plus emscripten etc.) from the mozilla infrastructure. (fetches the last emscripten version there)
* latest-upstream which installs upstream-llvm (plus emscripten etc.) from the waterfall infrastructure. (fetches the last known good revision (lkgr) there)
* latest-fastcomp which installs fastcomp-llvm (plus emscripten etc.) from the waterfall infrastructure. (fetches the last known good revision (lkgr) there)
The first and last are currently somewhat overlapping in that both fetch a build of fastcomp. However, as we transition away from the mozilla infrastructure, we could just make latest an alias for latest-fastcomp. (And later, when we're ready to switch to the wasm backend by default, the alias could switch to latest-upstream.)
This makes it possible to tell the emsdk to get "latest-upstream", which fetches the latest lkgr from there. This will probably be a common use pattern, I expect we may want to recommend users start trying out the wasm backend that way soon. This will also let us simplify this code: https://github.com/kripken/emscripten/blob/incoming/.circleci/config.yml#L334
Aside from adding the "latest-upstream" alias, this PR has
* A few minor cleanups in the emsdk code.
( Minor restructuring of how we define the upstream stuff in the manifest: It seemed odd to have 3 things (clang, emscripten, binaryen) that are all coming from a single archive from the waterfall. Simpler to have just one - the archive is one big lump, there's no way to download just part of it.
* Also add node 8.9.1 as a dependency of the upstream sdk, which makes things usable out of the box (node.js is the one thing not provided by the waterfall archive).
