RFR: 8211384: Obsolete -XX:+/-MonitorInUseLists option

[Claes Redestad]

Hi,

MonitorInUseLists was deprecated in JDK 10 and should be obsoleted. 
Doing this in 12 seems appropriate since it's the first in a series of 
non-LTS releases.

Webrev: http://cr.openjdk.java.net/~redestad/8211384/jdk.00/
Bug: https://bugs.openjdk.java.net/browse/JDK-8211384

Going over the code removal for this I've tried to rewrite comments to 
better reflect the current behavior (+MonitorInUseLists), and took the 
liberty to remove some redundant ones.

Testing: hs-tier1-2

Thanks!

/Claes