RFR: 8197991: Selecting many items in a TableView is very slow [v6]

[Ajit Ghaisas]

On Fri, 7 Jan 2022 08:04:53 GMT, Abhinay Agarwal <duke at openjdk.java.net> wrote:

>> This work improves the performance of `MultipleSelectionModel`  over large data sets by caching some values and avoiding unnecessary calls to `SelectedIndicesList#size`. It further improves the performance by reducing the number of iterations required to find the index of an element in the BitSet.
>> 
>> The work is based on [an abandoned patch](https://github.com/openjdk/jfx/pull/127) submitted by @yososs
>> 
>> There are currently 2 manual tests for this fix.
>
> Abhinay Agarwal has updated the pull request incrementally with two additional commits since the last revision:
> 
>  - Format code and reduce test size
>  - Add size assertion to test

The code changes look good.
I tested on Mac. This PR drastically improves the selection time for the provided manual test.

-------------

Marked as reviewed by aghaisas (Reviewer).

PR: https://git.openjdk.java.net/jfx/pull/673