Binding operators are incorrectly marked dead

[sim642]

Running reanalyze 389dd68 on Goblint goblint/analyzer@a544002 revealed the following.

In a file we have this binding operator definition:

let (let+) xs f = List.map f xs

This is marked dead even though the operator is used later in the file. I'm guessing reanalyze just doesn't handle this newer syntactic structure.

[cristianoc]

The implementation uses an AST mapper. Looks like this is a let-op, which is handled by ast mappers as a new form of binding. So indeed that seems to be the issue.
Also, several versions of typed AST are supported, from 4.06 to latest, so this would need to be injected a bit carefully using the tricks from the Compatibility module.