Friend of mine said he worked with a system like that. Problem with it was it couldn't save code that didn't compile. That's a defect. Am reminded of someones comment that they would like a compiler that just stubs out code that doesn't compile. For a system to be workable you need to be able to handle that.
I feel that because no one uses AST aware editors no one understands what that would bring to the table. A counter example I've used CAD programs. And all of them store the design files as databases internally. Which means you can and people do preform database operations on them. Generate reports and perform update operations just like you would with an SQL type database.