Alternatives to row_mins_c

[kbenoit]

https://stackoverflow.com/a/69195111/4158274

matrixStats::rowMins()

and what about ties?

[schochastics]

row_mins_c is giving the same results as matrixStats::rowMins() but is slightly faster because it is optimized for our case. One could surely opt for matrixStats::rowMins() but that would add a dependency that is not necessary.

Concerning ties: We only need the minimum value in a row, not its index (but @chainsawriot sould confirm that)

[chainsawriot]

@schochastics Regarding ties: Yes, we only need the minimum value.