ValueTypes attribute consistency checking and static fields

[Karen Kinnear]

Frederic and I have worked on a set of proposals for ValueTypes consistency checking.

http://cr.openjdk.java.net/~acorn/value-types-consistency-checking-details.pdf

The first part contains the proposal.

The second walks through details of the consistency checking in the case of a value type missing from
the ValueTypes attribute. The third walks the details in the case of a non-value type in the ValueTypes attribute.

The goal is to implement the consistency checking for LW1. Reviews appreciated. Suggestions on simpler
ways to express the details are also welcome.

The proposal also walks through a possible (post-LW1) approach for handling static fields that can contain
an instance of the same type.

I did not explore Value-Based-Class migration here yet, since that adds significant complexity.

thanks,
Karen