PROBLEM:
[$rd1 read] reads invalidation messages one by one, so it's never going to see the second invalidation message produced after INCR b, whether or not it exists. Adding another read will block incase no invalidation message is produced.
FIX:
We switch the order of "INCR a" and "INCR b" - now "INCR b" comes first. We still only read the first invalidation message produces. If an invalidation message is wrongly produces for b - then it will be produced before that of a, since "INCR b" comes before "INCR a".
Co-authored-by: Nitai Caro <caronita@amazon.com>
(cherry picked from commit 8fb89a572892e600146bd933c4f8f99d46a519c7)
