An intrinsic was declared without being a function.
Erroneous code example:
```compile_fail,E0622
#![feature(intrinsics)]
extern "rust-intrinsic" {
pub static breakpoint : unsafe extern "rust-intrinsic" fn();
// error: intrinsic must be a function
}
fn main() { unsafe { breakpoint(); } }
```
An intrinsic is a function available for use in a given programming language
whose implementation is handled specially by the compiler. In order to fix this
error, just declare a function.