[Tracking Issue] Julia Cooperative Multithreading Benchmarks

[NHDaly]

This is a tracking issue tracking our experiments benchmarking Julia's new cooperative multithreading (experimentally introduced in Julia v1.3 via @spawn).

List of Experiments:

• "Independent tasks" parallelism scaling experiment: Independent tasks parallelism scaling experiment #2
• "All threads allocating" parallelism scaling experiment: All threads allocating parallelism scaling experiment #3
• "One thread allocating" parallelism scaling experiment: [WIP] One thread allocating parallelism scaling experiment #4
• "All threads compiling" parallelism scaling experiment: [WIP] All threads compiling parallelism scaling experiment #5