HashBuild cpu regression

```
./dwarf_bench HashBuild --input_size=128 --device=cpu
DWARF_BENCH_ROOT is set to /build
You can change that with 'export DWARF_BENCH_ROOT=/your/path'
Selected device: Intel(R) Core(TM) i7-9700K CPU @ 3.60GHz
Incorrect results
double free or corruption (!prev)
Aborted (core dumped)```