Codegen is the same, but `begin_dealloc_ref` consumes the operand and produces a new SSA value.
This cleanly splits the liferange to the region before and within the destructor of a class.
For example:
```
var p = Point(x: 10, y: 20)
let o = UnsafePointer(&p)
```
Also support outlined arrays with pointers to other globals. For example:
```
var g1 = 1
var g2 = 2
func f() -> [UnsafePointer<Int>] {
return [UnsafePointer(&g1), UnsafePointer(&g2)]
}
```
The `bare` attribute indicates that the object header is not used throughout the lifetime of the value.
This means, no reference counting operations are performed on the object and its metadata is not used.
The header of bare objects doesn't need to be initialized.
