Delete the `Scope(const GraphType &&)` constructor, in order to avoid
potential bugs due to the storage of a temporary reference in the `const
GraphType &Graph` member.
Implement the `Inverse<Scope<...>>` `GraphTraits`. This are needed in
order to support the computation of the `PostDominatorTree` on a
`ScopeGraph`.
Add some `FileCheck` tests to test the dominator and postdominator trees
on the `ScopeGraph`.
Introduce the `EagerMaterializationRangeIterator`, which substitutes the
`GeneratorIterator`, and is used to materialize the successors of a
node in the `ScopeGraph`.
In addition, remove the `GeneratorIterator`.
Introduce the `ScopeCloser` and `GotoTarget` annotations in the IR, and
the relative necessary machinery, needed to handle scope closer and goto
edges for the new backend.
A specialization of the `llvm::GraphTraits`, called `ScopeGraph`, that
is able to handle both the above mentioned annotations is provided.
For the `llvm::GraphTraits` implementation, we introduce the
`GeneratorIterator` class, which uses a coroutine to store the status of
the iteration.
A debug logger pass is added, so that we are able to test the
functionality with `FileCheck`.
Andrea Gussoni