RFR [9] 8071474: Better failure atomicity for default read object

[Chris Hegarty]

The current implementation of defaultReadObject sets non-primitive field 
values one at a time, without first checking that all their types are 
assignable. If, for example, the assignment of the last non-primitive 
value fails, a CCE is thrown, and the previously set fields remain set. 
The setting of field values, including primitives, can be deferred until 
after they have been "validated", at a minimum that the non-primitive 
types are assignable. This is achievable per Class in the hierarchy up 
until the first user visible affect, i.e. a readObject(NoData) method. 
Either all fields will be set, or contain their default values.

http://cr.openjdk.java.net/~chegar/8071474/webrev.00/webrev/

I think there are further improvements that can be made in this area, 
but I would like to move things forward incrementally.

-Chris.