{:then} without name for resolving value will not compile in certain circumstances

[dekdevy]

Describe the bug
In {await} ... {:then} blocks, not specifying a name for the resolving value will cause an error which is hard to trace back to the issue. It only happens when the block contains another block(?).
This did not happen in 3.15.0.

(plugin svelte) Error: Not implemented Empty

To Reproduce
https://svelte.dev/repl/0eb341643bb4465ca47616f8b1cf2091?version=3.16.0
https://svelte.dev/repl/0eb341643bb4465ca47616f8b1cf2091?version=3.15.0

[Conduitry]

Fixed in 3.16.1 - https://svelte.dev/repl/0eb341643bb4465ca47616f8b1cf2091?version=3.16.1