libbindgen fails with "How?"

[Nashenas88]

The following code:

typedef void (Tcl_FSDupInternalRepProc) ();
extern Tcl_FSDupInternalRepProc TclNativeDupInternalRep;

Triggers the "How?" panic in libbindgen/src/codegen/mod.rs:2008 reproduced here:

        let signature = match *signature.kind() {
            TypeKind::Function(ref sig) => sig,
            _ => panic!("How?"), // << This line
        };

Changing it to:

        let signature = match *signature.kind() {
            TypeKind::Function(ref sig) => sig,
            ref ty => panic!("How? {} {:?}", name, ty), // << This line
        };

Outputs: How? TclNativeDupInternalRep ResolvedTypeRef(ItemId(1))

I was hoping to use libbindgen to move away from Tcl without needed to jump to C++, but the above declaration style is used all over the Tcl headers. (It's of course been cleaned up, macros and extra typedefs removed).

[fitzgen]

Thanks for the bug report!