Refactorer breaks imports

[Rua]

Currently visible in the CI output of #1620. The transpiler produces the right code, but the refactorer mishandles it afterwards.

[Rua]

@ahomescu Could this be related to tuple structs? That's the only thing that's really changed in that PR, and I don't think the transpiler normally emits tuple structs in any other situation. And it also seems to have something to do with the C2Rust_Unnamed* ones specifically.

[Rua]

Looking at the CI output of #1620 more, there are a lot of lines like this one:

pub const IPPROTO_ENCAP: crate::stdlib::C2Rust_Unnamed_2 = C2Rust_Unnamed_0(98);

The path in the constructor expression is not the same as the one used for the type. It's unqualified, and it also uses a different type name. It seems as though the process that renames the type annotation is not renaming the constructor expression in tandem?