When a heap was released at the same time as the last resource on that
heap, it was possible for both to see each other's
refcount/resource_count as 0 and both would try to destroy the heap.
Avoid that by converting "resource_count" to an internal refcount, which
holds an extra +1 if the main refcount is nonzero. The final release
will then be synchronized between the two since both will operate on
"internal_refcount".
We're already implicitly using it for image layouts in which
either depth or stencil is writeable and the other is not.
Correspondingly, add the _KHR suffix in those cases, so the
extension usage is more evident.
According to the Vulkan Hardware Database, only four reports
without this extension were filed since 2023, and all of them
for configurations we likely don't target.
So we avoid hardcoding that it is number zero. There are two
goals here: first making the code easier to understand and
second allow reshuffling the descriptor set allocation in a
later commit.
Like we did before commit 6d4782ed7f. That
commit somehow managed to change the "desc" field from
D3D12_RESOURCE_DESC to D3D12_RESOURCE_DESC1, but that breaks the ABI.
