RFR: VSC++ complains about multiple assignment operators

[Zhengyu Gu]

VSC++ complains about multiple assignment operators, so silence it.

c:\workspace\sh-jdk\src\hotspot\share\gc/shenandoah/shenandoahTaskqueue.hpp(176) 
: error C2220: warning treated as error
  - no 'object' file generated
c:\workspace\sh-jdk\src\hotspot\share\gc/shenandoah/shenandoahTaskqueue.hpp(176) 
: warning C4522: 'ObjArrayChunkedTask'
: multiple assignment operators specified

Webrev: 
http://cr.openjdk.java.net/~zgu/shenandoah/multi-assignment/webrev.00/

Test:

   Build on Windows.

Thanks,

-Zhengyu