RFR(XS): Leak mutex in ShenandoahTaskTerminator

[Roman Kennke]

Am 19.07.2017 um 20:18 schrieb Aleksey Shipilev:
> On 07/19/2017 08:13 PM, Zhengyu Gu wrote:
>> Another obvious one (my bad!)
>>
>> Webrev: http://cr.openjdk.java.net/~zgu/shenandoah/sh_terminator_memleak/webrev.00/
> Yup!
>
> -Aleksey
>
Please check if it applies to 9 and 8 and backport if necessary. Same
for the other leak fix.

Roman