[C++] More efficient implementation of exclusive publication position.
[C++] More efficient implementation of exclusive publication position.

EvilMcJerkface/Aeron,galderz/Aeron,real-logic/Aeron,mikeb01/Aeron,EvilMcJerkface/Aeron,real-logic/Aeron,real-logic/Aeron,real-logic/Aeron,mikeb01/Aeron,mikeb01/Aeron,galderz/Aeron,EvilMcJerkface/Aeron,galderz/Aeron,EvilMcJerkface/Aeron,mikeb01/Aeron,galderz/Aeron