RFR: 8186958: Need method to create pre-sized HashMap [v7]

[XenoAmess]

On Sat, 26 Mar 2022 10:53:05 GMT, Chris Hegarty <chegar at openjdk.org> wrote:

> You probably wanna allow for a non-NEW instance for the corner case where the given size is 0 - no elements.

@ChrisHegarty I guess we shouldn't.

I want to make it 100% equals to `new HashMap()` constructor, thus migrate all usecases.

So if we apply this, and when the original usage use this map object as a lock, or put some elements after the call(sometimes people cannot decide if they would really put elements in this map), bad things would happen.

Besides, there already a function` Map.of()` for such functionality, so programmer should use that instead if they really want a shared empty map.

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PR: https://git.openjdk.java.net/jdk/pull/7928