Migrate `stmt` naming to operate on the aast
Summary:
We want to remove the "legacy" AST and unify it with the AAST. To do this, we need to convert the `Naming` module, which currently operates over the legacy AST, to be able to use the AAST.
This diff converts the `stmt` functionality from using the AST to using the AAST.
To do this, we alias hint to use the Ast_to_nast module to convert the Ast.stmt to a Aast.stmt and then use the newly created function to perform naming.
`aast_stmt` was written in
D13642183. This diff simply uses `aast_stmt` in place of `stmt` in all places, not just in `expr`.
Reviewed By: arun11111
Differential Revision:
D13681620
fbshipit-source-id:
8278066bf415b99f2eb91a0e37d28e4d97b23f01