Benchmarks for Zig's std.HashMap. Will be expanded on in the future.

Based loosely on some of the benchmarking of C++ hash map implementations here:

• https://probablydance.com/2017/02/26/i-wrote-the-fastest-hashtable/
• https://tessil.github.io/2016/08/29/benchmark-hopscotch-map.html
• https://martin.ankerl.com/2019/04/01/hashmap-benchmarks-01-overview/
• https://github.com/ktprime/emhash#other-benchmark

Insertion without ensureCapacity:

zig run insert.zig -OReleaseFast -lc

zig run insert-strings.zig -OReleaseFast -lc

Output will be in the format:

num_elements,nanoseconds_per_element
1,68
2,40
3,32
5,25
7,21
10,19
...