std: add warm up phase to benchmark
std: add warm up phase to benchmark

In my tests, whatever ran first was getting much better numbers.
Additionally, add alignment requirements so that comparison is fair.

zig-lang/zig,andrewrk/zig,raulgrell/zig,raulgrell/zig,zig-lang/zig,raulgrell/zig,zig-lang/zig,andrewrk/zig,raulgrell/zig,raulgrell/zig