RFR(XS): Use lock version memory allocator

[Roman Kennke]

If I remember correctly, this throws asserts in debug mode. It wants an acquired Heap_lock.

RomanAm 27.02.2017 5:12 nachm. schrieb Zhengyu Gu <zgu at redhat.com>:
>
> Use lock version of heap region memory allocator. 
>
> Webrev: http://cr.openjdk.java.net/~zgu/shenandoah/memory_allocate/webrev.00/ 
>
> Test: 
>    fastdebug/release jdk: specjvm Derby 
>
>
> Thanks, 
>
> -Zhengyu 
>