Opaque type should not have `pub` member

For a type that is explicitly marked opaque via .opaque_type("Foo"), bindgen generates a type with a public member:

#[repr(C)]
#[repr(align(4))]
#[derive(Debug, Default, Copy, Clone)]
pub struct BAR__ {
    pub _bindgen_opaque_blob: u32,
}

Shouldn't _bindgen_opaque_blob be generated without pub? Making it pub allows the user to directly instantiate an instance of BAR__ which is most likely invalid, which defeats the purpose of it being an opaque type

Other Information
rust-bindgen 0.71.1
clang version 19.1.7
Target: x86_64-pc-windows-msvc

Full Code Sample
build.rs:

use std::env;
use std::path::PathBuf;

fn main() {
    tracing_subscriber::fmt::init();

    let builder = bindgen::Builder::default()
        .header_contents(
            "input.h",
            r#"
struct Foo;

struct BAR__{int unused;};
typedef struct BAR__ *BAR;
"#,
        )
        .parse_callbacks(Box::new(bindgen::CargoCallbacks::new()))
        .derive_default(true);

    let out_path = PathBuf::from(env::var("OUT_DIR").unwrap());

    builder
        .clone()
        .generate()
        .expect("Unable to generate bindings")
        .write_to_file((out_path).join("not-explicit-opaque.rs"))
        .expect("Couldn't write bindings!");

    builder
        .opaque_type("Foo")
        .opaque_type("BAR__") // Only BAR__ should be marked as opaque. The convenience type BAR should remain as a pointer to the opaque BAR__. 
        .generate()
        .expect("Unable to generate bindings")
        .write_to_file((out_path).join("explicit-opaque.rs"))
        .expect("Couldn't write bindings!");
}

Output:
not-explicit-opaque.rs:

/* automatically generated by rust-bindgen 0.71.1 */

#[repr(C)]
#[derive(Debug, Copy, Clone)]
pub struct Foo {
    _unused: [u8; 0],
}
#[repr(C)]
#[derive(Debug, Default, Copy, Clone)]
pub struct BAR__ {
    pub unused: ::std::os::raw::c_int,
}
#[allow(clippy::unnecessary_operation, clippy::identity_op)]
const _: () = {
    ["Size of BAR__"][::std::mem::size_of::<BAR__>() - 4usize];
    ["Alignment of BAR__"][::std::mem::align_of::<BAR__>() - 4usize];
    ["Offset of field: BAR__::unused"][::std::mem::offset_of!(BAR__, unused) - 0usize];
};
pub type BAR = *mut BAR__;

explicit-opaque.rs:

/* automatically generated by rust-bindgen 0.71.1 */

#[repr(C)]
#[derive(Debug, Default, Copy, Clone)]
pub struct Foo {
    _unused: [u8; 0],
}
#[repr(C)]
#[repr(align(4))]
#[derive(Debug, Default, Copy, Clone)]
pub struct BAR__ {
    pub _bindgen_opaque_blob: u32,
}
#[allow(clippy::unnecessary_operation, clippy::identity_op)]
const _: () = {
    ["Size of BAR__"][::std::mem::size_of::<BAR__>() - 4usize];
    ["Alignment of BAR__"][::std::mem::align_of::<BAR__>() - 4usize];
};
pub type BAR = *mut BAR__;

Output Diff (left is no explicit opaque. right is explicit opaque):

Start with the bindgen Builder configuration in build.rs and the .opaque_type("BAR__") path; compare explicit-opaque.rs with not-explicit-opaque.rs. Find or add a regression test for generated opaque fields, and verify that the generated blob cannot be directly instantiated while BAR remains a pointer to BAR__.