Miner: Memory usage has gone up from 0.5gb to 2gb

[neoneye]

@kotenok2000 has run a git bisect and found the commit.

When i run commit d24d68f loda-rust reaches 532 mb.

When i run commit 81a0592 reaches 2 GB

I cannot see what should be causing the memory to grow. The n'th root code is based on the logarithm code and they are nearly identical, the n'th root is slightly longer. I'm surprising that it impacts memory usage so much. Very weird. The compute_nthroot() does BigUint manipulation. While mining it can be that it frequently hits a code path that causes the compute_nthroot() to end up returning an error. I don't see how this should be leaking memory.

Screenshot of memory usage, see the highlighted row with the loda-rust mine process.

Thanks to @kotenok2000 for reporting this issue.