Fix named constructors and static methods of hidden native classes.

Fix named constructors and static methods of hidden native classes.

The static methods can't go on the constructor, so they go on a
surrogate object.  Make sure no global names conflict with either the
hidden class's name or the surrogate object.

BUG=
TEST=

Committed: https://code.google.com/p/dart/source/detail?r=2547

[Jennifer Messerly, 2011-12-16 22:09:34]

I'm getting a feeling of creeping complexity of natives. But this change lgtm
:). Nice targeted fixes.

Maybe add a TODO about the renaming in world being more complex than it needs to
be because of the incrementalness.