I think I understand #17563, and I should fix GROWTH_RATE.

Before compact-ordered dict, we can avoid resizing in
"the number of deletions is on a par with the number of insertions."
scenario, by large GROWTH_RATE.
That's because new entry can reuse dummy entries.

But in compact-ordered dict, we can't do that.
We need resizing always, and resize is much faster than legacy dict.

I think GROWTH_RATE should be ma_used*3 for now.