I found that the initial corpus allocation of fork mode has certain defects.
I designed a new initial corpus allocation strategy based on size grouping.
This method can give more energy to the small seeds in the corpus and
increase the throughput of the test.
Fuzzbench data (glibfuzzer is -fork_corpus_groups=1):
https://www.fuzzbench.com/reports/experimental/2021-08-05-parallel/index.html
Instead of passing Group as a parameter everywhere, could we add it to FuzzerOptions and just use Options.Group?