error: lifetime may not live long enough
  --> $DIR/issue-95272.rs:10:13
   |
LL | fn test<'a, 'b>(x: Cell<&'a ()>, y: Cell<&'b ()>) {
   |         --  -- lifetime `'b` defined here
   |         |
   |         lifetime `'a` defined here
LL |     let f = check;
   |             ^^^^^ assignment requires that `'a` must outlive `'b`
   |
   = help: consider adding the following bound: `'a: 'b`
   = note: requirement occurs because of a function pointer to `check`
   = note: the function `check` is invariant over the parameter `'a`
   = help: see <https://doc.rust-lang.org/nomicon/subtyping.html> for more information about variance

error: aborting due to 1 previous error