Severe invokers performance drop from OpenJDK 7 to OpenJDK 8

[Julien Ponge]

> I think it may be useful to specify which version of OpenJDK 7 was used as significant differences exist.

Recent tries have been made on Oracle JDK for MacOSX:
Java HotSpot(TM) 64-Bit Server VM (build 23.7-b01, mixed mode)

>>   * Under OpenJDK 8 I get ~0.75s in the same conditions, which is
>>     severely slower.
> 
> Probably useful to say which build was used here too

Custom build from jdk8/jdk8. The behaviour has been observed for some
time. Here I have a build from last month:
OpenJDK 64-Bit Server VM (build 25.0-b50, mixed mode)

- Julien