When trying to update bindgen, functions that looked like: ```rust extern "C" { pub fn Gecko_GetAnonymousContentForElement(element: RawGeckoElementBorrowed) -> *mut nsTArray<*mut nsIContent>; } ``` Now look like: ```rust extern "C" { pub fn Gecko_GetAnonymousContentForElement(element: RawGeckoElementBorrowed) -> *mut u64; } ``` Which means that there was probably a regression in how we detect opaque types and such. Bisecting now.