RFR: 8073669 - gc/TestSoftReferencesBehaviorOnOOME.java times out in nightlies

[Andrey Zakharov]

Hi, team.
gc/TestSoftReferencesBehaviorOnOOME.java times out in nightlies.
Ignore it for a while due its unstable even locally - GC Overtime, 
unexpected OOM and timeouts in a wild.
Need more time to fix it.

webrev:
http://cr.openjdk.java.net/~azakharov/8073669/webrev/

testbug:
https://bugs.openjdk.java.net/browse/JDK-8073669

Thanks.