Change Details

- Added accumulators and checks on benchmarks so they won't get optimized out - Modified bench_scalar_split so it won't get optimized out

- Added accumulators and checks on benchmarks so they won't get optimized out - Modified bench_scalar_split so it won't get optimized out This is a backport of libsecp256k1 PR678

- Added accumulators and checks on benchmarks so they won't get optimized out - Modified bench_scalar_split so it won't get optimized out This is a backport of libsecp256k1 PR678