RFR(14u): 8237375: SimpleThresholdPolicy misses CounterDecay timestamp initialization

[Langer, Christoph]

Hi,

please help reviewing the backport of the following change to jdk14u:

Bug: https://bugs.openjdk.java.net/browse/JDK-8237375
Original change: https://hg.openjdk.java.net/jdk/jdk/rev/2a0e2304e68b
Webrev: http://cr.openjdk.java.net/~clanger/webrevs/8237375.14u/

The original change would not apply due to its predecessor "8235741: Inappropriate uses of os::javaTimeMillis()" which isn't backported. I had to do some context shifting and replace usage of method nanos_to_millis, since this was only introduced with 8235741.

Thanks
Christoph