This did not show up earlier because
we used soft class references, which
reduces the memory footprint of unused
TypeSystems. However, they still remain
in old gen and are a large memory hog.
Since e97e2cd we don't use SoftReference
anymore as parsing the same class several
times may have unintended side-effects.
This revealed the out of memory error.
This will be fixed when we have proper
language lifecycle and resources like the
classloader can be reclaimed later.
99425d53ff