From Magnus' review mail:

* I think the jdk/make/data directory could (and should) be separated on module level, e.g. jdk/make/data/java.base/... etc. Or, maybe, that the contents should even be moved out into like src/java.base/share/data, since the contents of that directory in a way is "source code" (only just not Java or native source code), and not really part of the build system.