RFR: Add asserts all over synchronizer

[Roman Kennke]

Aleksey pointed out in private that we could just as well make
synchronizer and biasedlocking use oopDesc::cas_set_mark() and then put
the asserts there and in oopDesc::set_mark() and
oopDesc::release_set_mark(). That should give us better coverage. So
here it is:

http://cr.openjdk.java.net/~rkennke/assertsynchronizer/webrev.01/

Ok now?

Roman


Am Donnerstag, den 06.10.2016, 18:09 +0200 schrieb Roman Kennke:
> I've seen an assert in synchronizer, and want to make sure than
> whenever the mark word is modified by synchronizer, the object really
> is in to-space and safe to write. This patch adds assert all over the
> place, wherever the mark word is modified by synchronizer and biased
> locking. I hope I found all the places...
> 
> http://cr.openjdk.java.net/~rkennke/assertsynchronizer/webrev.00/
> 
> Ok to push?
> 
> Roman