Blacklisting functions/items doesn't seem to work with Blocks

Quite related to https://github.com/rust-lang/rust-bindgen/issues/1706

I've tried a number of things and this doesn't seem to fix or remove the generated block type alias.

Input C/C++ Header

// bindgen-flags:  --blacklist-function enumerateObjectsUsingBlock  --blacklist-type FooWithBlock* --generate-block --objc-extern-crate --block-extern-crate  -- -x objective-c -fblocks
// bindgen-osx-only

@interface FooWithBlock<__covariant ObjectType>
- (void)enumerateObjectsUsingBlock:(void (^)(ObjectType obj, int idx))block;
@end

Bindgen Invocation

$ bindgen input.h --blacklist-function enumerateObjectsUsingBlock  --blacklist-type FooWithBlock* --generate-block --objc-extern-crate --block-extern-crate  -- -x objective-c -fblocks

Actual Results

/* automatically generated by rust-bindgen */

pub type _bindgen_ty_id_5 =
    *const ::block::Block<(*mut ObjectType, ::std::os::raw::c_int), ()>;

Expected Results

Nothing I would think.

Start by reproducing the bindgen invocation in the issue with the Objective-C header and block-related flags. Trace how blacklist-function and blacklist-type are applied to generated block aliases; done means the reported _bindgen_ty_id_5 alias is absent from the generated bindings.