RFR: Simplify parallel synchronizer roots iterator

[Roman Kennke]

Am 10.05.2017 um 16:14 schrieb Aleksey Shipilev:
> On 05/10/2017 04:11 PM, Roman Kennke wrote:
>> http://cr.openjdk.java.net/~rkennke/simplify-sync-roots/webrev.01/
> The idea sounds fine.
>
>  *) my_cur and next_block variables could be *void, to avoid clutter?
Infact, I made them be ObjectMonitor* instead, and also let claim()
return ObjectMonitor*. This looks like the usual way to ignore PaddedEnd
unless where it's needed (e.g. below in iteration code).
>  *) I still see the asserts that reference CLAIMEDMARKER -- does it even build
> with fastdebug?
Oops.

Also, we don't need the destructor anymore to restore CHAINEDMARKER, and
we also don't need _head anymore. Yippie!

http://cr.openjdk.java.net/~rkennke/simplify-sync-roots/webrev.02/
<http://cr.openjdk.java.net/%7Erkennke/simplify-sync-roots/webrev.02/>

Ok now?

Roman