JEP 248: Make G1 the Default Garbage Collector

[Dawid Weiss]

> The real concern brought up in this thread is the miscompilation causing
> corruption in lucene.

...which we only have a strong suspicion is related to G1, not a
guarantee. It's also a very tough nut to crack (reproduce reliably or
even diagnose on those runs that failed). For all we know, it could be
an interaction between several things at once producing this unstable
behavior.

Dawid