QtTest LoggerRegistry: fix UB (insufficient atomic memory order)

The code load()s the shared `loggers` to iterate over it (or copy from
it) (= read the memory pointed to) and it store()s the shared
`loggers` after intializing it (= writing to the memory pointed to).

So relaxed loads and stores are not sufficient here. Stores must have
release memory order and loads acquire memory order, otherwise the
writes before the store() will not happen-before the reads after the
load(), which is a data race, which is UB. The fact that the pointer
is a shared_ptr doesn't change that.

Amends a0303cc7c590ff17fb5b0a5975bff98669e42942.

Pick-to: 6.10 6.9 6.8
Change-Id: I8f82e5db240efdd414983f5b1cb0e1c1f1861100
Reviewed-by: Tim Blechmann <[email protected]>
Reviewed-by: David Faure <[email protected]>

0 files changed, 0 insertions, 0 deletions