Issue 3551
This change adds const as a valid keyword to declare fields and
variables. The mandatory initializer has to be a compile time
const expression.
Static final variables still have to be initialized with
compile time constant expressions. I will add non-const static
finals (issue 3558) in another change.
Other small changes:
- allow null in some compile time constant expressions.
- allow only numbers, booleans, strings and null in compile time
constant string interpolation.
Review URL: https://chromiumcodereview.appspot.com//10828053
git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@9992 260f80e4-7a28-3924-810f-c04153c831b5
lrn@google.com