[Bug][move-compiler-v2] Copy mutable ref twice for ==

[zzjas]

🐛 Bug

module 0xCAFE::Module0 {
    public fun function2() {
        let x = &mut 0u8;
        (copy x == copy x);
    }
}

This compiles with V1, but V2 will report:

error: mutable reference in local `x` requires exclusive access but is borrowed
  ┌─ ~/debug_package/sources/repro.move:4:20
  │
4 │         (copy x == copy x);
  │         -----------^^^^^^-
  │         │          │
  │         │          requirement enforced here
  │         conflicting reference used here

error: same mutable reference in value is also used in other value in argument list
  ┌─ ~/debug_package/sources/repro.move:4:9
  │
3 │         let x = &mut 0u8;
  │                 -------- previous mutable local borrow
4 │         (copy x == copy x);
  │         ^^^^^^^^^^^^^^^^^^ requirement enforced here

The operations are safe so probably just a difference in V1/V2's ref safety algorithm.