RFR: 8015759: hotspot changes needed to compile with Visual Studio 2012

[Tim Bell]

8015759: hotspot changes needed to compile with Visual Studio 2012

The bug report will be visible in a few days here:
http://bugs.sun.com/view_bug.do?bug_id=8015759

Minor Makefile changes and one source file was touched to compile with 
Visual Studio 2012.  These changes also compile under
Visual Studio 2010 with no problem so we can upgrade gracefully.  Tested 
by building the forest with both compilers.

% hg status
M make/windows/makefiles/compile.make
M make/windows/makefiles/sanity.make
M make/windows/makefiles/vm.make
M src/os_cpu/windows_x86/vm/unwind_windows_x86.hpp

webrev and patch file are here:

http://cr.openjdk.java.net/~tbell/8015759/hotspot/webrev.00/
http://cr.openjdk.java.net/~tbell/8015759/hotspot/webrev.00/hotspot.patch

Thanks to Anthony Petrov who provided the initial set of patches for 
this work.

I believe this should go in via the hotspot-rt forest (let me know if 
that is not correct), in which case I will need a sponsor from that team 
to push the change.

Thanks in advance-
Tim