message: fix oom2 test
diff: // Validation forces more allocation; disable it.
  // compile-flags: -Zmir-emit-validate=0
  #![feature(box_syntax, custom_attribute, attr_literals)]
  -#![miri(memory_size=2048)]
  +#![miri(memory_size=1024)]
  +
  +// On 64bit platforms, the allocator needs 32 bytes allocated to pass a return value, so that's the error we see.
  +// On 32bit platforms, it's just 16 bytes.
  +// error-pattern: tried to allocate
  fn main() {
  loop {
  - ::std::mem::forget(box 42); //~ ERROR tried to allocate 4 more bytes
  + ::std::mem::forget(box 42);
  }
  }
  