The consequence of this issue was that in some very rare cases (only reproduced
under load in CI when running 4+ tests in parallel) small write data written to
journal could overwrite journal entries.
Also add an assert-type safety check to be able to catch this issue in the
future again in case of a regression.
Build problems fixed:
- void* pointer arithmetic which is a GNU extension (works as byte*)
- "variable size object may not be initialized" which is OK under GCC
- nullptr_t related error in json11 (it lacks 'operator <' in clang)
Warnings fixed:
- empty nested struct initializer { 0 } replaced by {}
- removed several unused lambda captures
Slightly reduces WA. For example, in 4K T1Q128 replicated randwrite tests
WA is reduced from ~3.6 to ~3.1, in T1Q64 from ~3.8 to ~3.4.
Only effective without no_same_sector_overwrites.