Indeed they will. Gaming compiler benchmarks has been going on since the early 1980's.
Datalight C was the first C compiler for DOS to do data flow optimizations. Since the benchmarks of the time simply did some operations and ignored the result, the data flow optimizations would delete the benchmark code.
I was accused of gaming and cheating on the benchmarks. After they published, of course. Sigh. It wasn't long before other compilers did DFA, and the benchmarks (of course) were changed.
But again some programming languages will probably going to optimize it to oblivion wink Julia wink.