[Feature request] Add option for aliasing common Rust types for its C++ equivalents

[DasMatus]

It'd be nice to have this, because then you don't have to mess with rewriting the whole codebase just to support FFI.

How it should look like:

If the code contains, for example, Vec<T>, then preprocessor macro will be added on top of header redefining Vec<T> to vector<T>. Same thing with HashMap<K, V> to map<K, V>.

Example:

• Rust file:

fn function() -> HashMap<String, String> {}

• Generated header:

#include <cstdarg>
#include <cstddef>
#include <cstdint>
#include <cstdlib>
#include <ostream>
#include <new>
#define HashMap map
#define String string

using namespace std
HashMap<String, String> function();