type-specialization prototype

[Maurizio Cimadamore]

Fellow vikings,
as you probably have noticed, I've start hacking [1] on the 
type-specialization prototype; the current state of this feature is 
captured in [2]. The first patch I've pushed adds support for the 'any' 
type-variable 'modifier'. Aside from allowing it in the parser (and 
setting a corresponding flag on the AST), the rest of javac is still 
'any' agnostic - I plan to extend the compiler support in the upcoming 
weeks, in order to add suitable semantics checks and bytecode 
representation. As part of this first changeset, I've also added a new 
source flag - 'valhalla' which is now being used as the default in the 
context of this project.

Keep comments flowing, and enjoy the ride - I'm sure it'll be a fun one :-)

Maurizio

[1] - 
http://hg.openjdk.java.net/valhalla/valhalla/langtools/rev/d9c7704baf6e
[2] - http://cr.openjdk.java.net/~briangoetz/valhalla/specialization.html