RFR: 8248346: Move OopStorage mutex setup out from OopStorageSet

[Kim Barrett]

> On Jun 25, 2020, at 3:40 PM, Stefan Karlsson <stefan.karlsson at oracle.com> wrote:
> 
> Hi all,
> 
> Please review this small patch to move the OopStorage mutex creation out from oopStorageSet.cpp and put it inside the OopStorage constructor.
> 
> https://cr.openjdk.java.net/~stefank/8248346/webrev.01
> https://bugs.openjdk.java.net/browse/JDK-8248346
> 
> So far I've only tested this locally with gtest. The product code should be the same, but the test used slightly different values when initializing the mutexes. That doesn't seem to affect the tests.
> 
> Thanks,
> StefanK

Looks good.