Benchmarker: Add a CLI param to set N

[WilliamTambellini]

As today the benchmarker benchs 4 cases of partialsort:

   MY_BENCHMARK_CAPTURE(func, type, k10, 10000, 10); \
    MY_BENCHMARK_CAPTURE(func, type, k100, 10000, 100); \
    MY_BENCHMARK_CAPTURE(func, type, k1000, 10000, 1000); \
    MY_BENCHMARK_CAPTURE(func, type, k5000, 10000, 5000);

x86-simd-sort/benchmarks/bench.h

Line 52 in 87486d1

MY_BENCHMARK_CAPTURE(func, type, k10, 10000, 10); \

For LLM inference the values are more extreme: N (vocab size) = 100000 or more, and k could be even smaller than 10.
Would you mind if I add a CLI arg to set at least N (ARRSIZE) ?

[r-devulap]

I'm not sure if there is way to add command line arguments in google benchmark. You are welcome to add more benchmarks that seem relevant to you.