The build system uses the "javac server" by default, which was part of the original smart javac (sjavac) effort. This works well.

We also support running the full sjavac. This is not tested regularly, and is likely to be broken. With the Jigsaw modularisation, and the javac server as described above, the benefits of the full sjavac is also very small.

We should remove support for the full sjavac from the build. It's currently just confusing. If the functionality from sjavac ever migrates into javac proper, we'll of course start using it again.