RFA Backport CSR to 11u: 8231194: ThreadMXBean::getThreadAllocatedBytes() can be quicker for self thread

[Hohensee, Paul]

Please review/approve an 11u CSR backport request.

https://bugs.openjdk.java.net/browse/JDK-8231194

Original issue: https://bugs.openjdk.java.net/browse/JDK-8207266
Original CSR: https://bugs.openjdk.java.net/browse/JDK-8230311
11u backport issue: https://bugs.openjdk.java.net/browse/JDK-8231193

Email threads:

https://mail.openjdk.java.net/pipermail/serviceability-dev/2019-August/029011.html
https://mail.openjdk.java.net/pipermail/serviceability-dev/2019-September/029033.html

Thanks,

Paul