RFR(xs): [windows] small fixes to os::check_heap()

[Christian Tornqvist]

Hi Thomas,

This looks good, thanks for fixing this.

Thanks, 
Christian

> On Nov 18, 2015, at 11:40 AM, Thomas Stüfe <thomas.stuefe at gmail.com> wrote:
> 
> Hi all,
> 
> could you please sponsor and review these tiny changes to os::check_heap()
> on windows:
> 
> webrev: http://cr.openjdk.java.net/~stuefe/webrevs/8143233/webrev.00/webrev/
> bug: https://bugs.openjdk.java.net/browse/JDK-8143233?filter=22798
> 
> Fixes two issues:
> - GetProcessHeap() is not necessarily the CRT heap, so we need to use
> _get_heap_handle(); instead
> - We need to always unlock the heap before exiting with fatal() in case we
> found an error.
> 
> Kind Regards, Thomas