Ractor: Fix moving embedded objects

[Bug #20271]
[Bug #20267]
[Bug #20255]

`rb_obj_alloc(RBASIC_CLASS(obj))` will always allocate from the basic
40B pool, so if `obj` is larger than `40B`, we'll create a corrupted
object when we later copy the shape_id.

Instead we can use the same logic than ractor copy, which is
to use `rb_obj_clone`, and later ask the GC to free the original
object.

We then must turn it into a `T_OBJECT`, because otherwise
just changing its class to `RactorMoved` leaves a lot of
ways to keep using the object, e.g.:

```
a = [1, 2, 3]
Ractor.new{}.send(a, move: true)
[].concat(a) # Should raise, but wasn't.
```

If it turns out that `rb_obj_clone` isn't performant enough
for some uses, we can always have carefully crafted specialized
paths for the types that would benefit from it.

0 files changed, 0 insertions, 0 deletions