JVMS draft for L-world value types with support for nullability

[Frederic Parain]

Here’s an update of the JVMS draft:

http://cr.openjdk.java.net/~fparain/L-world/L-World-JVMS-4.pdf

with the following changes:

  * Renamed ACC_NON_NULLABLE with ACC_FLATTENABLE
  * Removed restriction that ACC_FLATTENABLE cannot be used on static fields
  * Added rules about circularity restrictions for fields with the ACC_FLATTENABLE flag set
  * Added rules about initialization of classes of flattenable fields 

Fred