Binding for const <typedef-ed array type> has incorrect mutability

[unageek]

Input C/C++ Header

typedef int int1[1];
void f(const int1 x);

Bindgen Invocation

$ bindgen test.h

Actual Results

/* automatically generated by rust-bindgen 0.56.0 */

pub type int1 = [::std::os::raw::c_int; 1usize];
extern "C" {
    pub fn f(x: *mut ::std::os::raw::c_int);
}

Expected Results

The type of the parameter x should be *const ::std::os::raw::c_int:

/* automatically generated by rust-bindgen 0.56.0 */

pub type int1 = [::std::os::raw::c_int; 1usize];
extern "C" {
    pub fn f(x: *const ::std::os::raw::c_int);
}

[unageek]

It appears that we need to propagate self.is_const here:

https://github.com/rust-lang/rust-bindgen/blob/2aed6b0216805e27228ed39988ffe1a1ffd7e940/src/ir/ty.rs#L324-L328

But that is not possible because the method returns the canonical type by reference.

[wjyoumans]

Are there any workarounds for this? I'm using bindgen on some large-ish libraries and most of the binding arguments are mutable when they should be const. Manually correcting them takes a very long time, but it's the only fix I have for now.

Here's an example if it helps: https://github.com/wjyoumans/arb-sys/issues/2