8228392: java.io.Filter{In,Out}put stream constructors should allow null stream parameter

[Brian Burkhalter]

https://bugs.openjdk.java.net/browse/JDK-8228392
http://cr.openjdk.java.net/~bpb/8228392/webrev.00/

This moves the NPE from the Filter{In,Out}putStream constructors to the 
subclass constructors.

One thing which should be considered as an alternative would be not to check 
for null at all in these constructors but update the subclass constructor 
specifications to override the class documentation and indicate that the 
underlying stream parameter may be null.

This change has passed the tier 1-3 tests modulo one timeout of an unrelated 
tier 2 test.

Thanks,

Brian