This makes it not as easy to forgot to handle OOMs in the kernel.
This commit replaces most usages of this function with
`try_append(...).release_value_but_fixme_should_propagate_errors()`.
But in some cases, using the `TRY` macro or `unchecked_append()` is
already possible.
In places where allocations should not fail or an OOM would be fatal
anyways, `MUST(try_append(...))` should be used explicitly.
The implemented cloning mechanism should be sound:
- If a PartitionTable is passed a File with
ShouldCloseFileDescriptor::Yes, then it will keep it alive until the
PartitionTable is destroyed.
- If a PartitionTable is passed a File with
ShouldCloseFileDescriptor::No, then the caller has to ensure that the
file descriptor remains alive.
If the caller is EBRPartitionTable, the same consideration holds.
If the caller is PartitionEditor::PartitionModel, this is satisfied by
keeping an OwnPtr<Core::File> around which is the originally opened
file.
Therefore, we never leak any fds, and never access a Core::File or fd
after destroying it.
