Review request for JDK-8012334: ToUint32, ToInt32, and ToUint16 don't conform to spec

[Hannes Wallnoefer]

Please review webrev for JDK-8012334: ToUint32, ToInt32, and ToUint16 
don't conform to spec:

http://cr.openjdk.java.net/~hannesw/8012334/

The code path for small numbers is now a little bit slower but not much. 
The code path for large numbers  that don't fit in 32 bits is quite a 
bit slower, but it should be correct now. The patch also contains a 
microbenchmark for ToInt32 (signed right shift) and ToUint32 (unsigned 
right shift).

Hannes