ices/79690.rs: fixed with errors

[github-actions]

Issue: rust-lang/rust#79690

union Transmute<T: Copy, U: Copy> {
    t: T,
    u: U,
}
trait Bar {
    fn bar(&self) -> bool;
}
struct Foo {
    foo: bool,
    bar: bool,
}
impl Bar for Foo {
    fn bar(&self) -> bool {
        self.foo
    }
}
#[derive(Copy, Clone)]
struct Fat<'a>(&'a Foo, &'static VTable);
struct VTable {
    size: Foo,
}
const FOO: &Bar = &Foo {
    foo: true,
    bar: false,
};
const G: Fat = unsafe { Transmute { t: FOO }.u };

fn main() {}

=== stdout ===
=== stderr ===
warning: trait objects without an explicit `dyn` are deprecated
  --> /home/runner/work/glacier/glacier/ices/79690.rs:22:13
   |
22 | const FOO: &Bar = &Foo {
   |             ^^^ help: use `dyn`: `dyn Bar`
   |
   = note: `#[warn(bare_trait_objects)]` on by default

warning: union is never used: `Transmute`
 --> /home/runner/work/glacier/glacier/ices/79690.rs:1:7
  |
1 | union Transmute<T: Copy, U: Copy> {
  |       ^^^^^^^^^
  |
  = note: `#[warn(dead_code)]` on by default

warning: field is never read: `bar`
  --> /home/runner/work/glacier/glacier/ices/79690.rs:10:5
   |
10 |     bar: bool,
   |     ^^^^^^^^^

warning: field is never read: `size`
  --> /home/runner/work/glacier/glacier/ices/79690.rs:20:5
   |
20 |     size: Foo,
   |     ^^^^^^^^^

warning: constant is never used: `FOO`
  --> /home/runner/work/glacier/glacier/ices/79690.rs:22:1
   |
22 | / const FOO: &Bar = &Foo {
23 | |     foo: true,
24 | |     bar: false,
25 | | };
   | |__^

warning: constant is never used: `G`
  --> /home/runner/work/glacier/glacier/ices/79690.rs:26:1
   |
26 | const G: Fat = unsafe { Transmute { t: FOO }.u };
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error[E0080]: it is undefined behavior to use this value
  --> /home/runner/work/glacier/glacier/ices/79690.rs:26:1
   |
26 | const G: Fat = unsafe { Transmute { t: FOO }.u };
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered (potentially part of) a pointer at .1.<deref>.size.foo, but expected plain (non-pointer) bytes
   |
   = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.

error: aborting due to previous error; 6 warnings emitted

For more information about this error, try `rustc --explain E0080`.
==============