RFR: Fix assertion failure of matrix size due to vm allocation granularity on Win x64

[Roman Kennke]

That looks good to me.
Thanks,
Roman

> Oops.
> 
> http://cr.openjdk.java.net/~zgu/shenandoah/matrix_size/webrev.00/
> 
> -Zhengyu
> 
> On 12/20/2017 01:10 PM, Roman Kennke wrote:
>> Am 20.12.2017 um 18:15 schrieb Zhengyu Gu:
>>> This patch fixes assertion failure of TestGCThreadGroups on Windows x64.
>>>
>>>    Internal Error 
>>> (c:/Users/zhengyu/workspace/shenandoah-jdk10/src/hotspot/share/memory/virtualspace.cpp:103), 
>>> pid=6404, tid=4448
>>>    assert((size & (granularity - 1)) == 0) failed: size not aligned 
>>> to os::vm_allocation_granularity()
>>>
>>> On Windows x64, vm_allocation_granularity is 64K, instead of 4K.
>>>
>>>
>>> Webrev: 
>>> file:///home/zgu/webrevs/shenandoah/matrix_size/webrev.00/index.html
>>>
>>
>> You posted a link to a local webrev :-)
>>