Merge branch 'ps/reftable-fixes'
Bunch of small fix-ups to the reftable code.
* ps/reftable-fixes:
reftable/block: reuse buffer to compute record keys
reftable/block: introduce macro to initialize `struct block_iter`
reftable/merged: reuse buffer to compute record keys
reftable/stack: fix use of unseeded randomness
reftable/stack: fix stale lock when dying
reftable/stack: reuse buffers when reloading stack
reftable/stack: perform auto-compaction with transactional interface
reftable/stack: verify that `reftable_stack_add()` uses auto-compaction
reftable: handle interrupted writes
reftable: handle interrupted reads
reftable: wrap EXPECT macros in do/while