RFR: 8281631: HashMap.putAll can cause redundant space waste

[XenoAmess]

On Thu, 10 Feb 2022 17:46:36 GMT, XenoAmess <duke at openjdk.java.net> wrote:

> 8281631: HashMap.putAll can cause redundant space waste

According to the discussion at mailing list, we decide to try only change the calculation inside HashMap and WeakHashMap, and see what would happen.
The next step is fixing all such **size/0.75+1** in jdk (expected several hundreds places...)

I investigated most of the usages.
They just give a size, and get a capacity, even not change the 0.75
So maybe we can use some int calculation to replace the 0.75, thus replace Math.ceil for such situations.

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PR: https://git.openjdk.java.net/jdk/pull/7431