VM: Fix performance regression introduced by r28408.

VM: Fix performance regression introduced by r28408.

Change the AST for static consts so that they don't
end up translated as calls, and so that we don't rely
on the inliner to fold them away).

Instead I generate a LoadStatic AST node that will be
constant folded in the flow graph builder.

BUG=https://code.google.com/p/dart/issues/detail?id=13954

Committed: https://code.google.com/p/dart/source/detail?r=28521

[Kevin Millikin (Google), 2013-10-11 15:04:18]

lgtm

[hausner, 2013-10-11 15:46:05]

Thank you!