RFR: 6356745: Introduce constructor for PriorityQueue with existing collection and custom comparator

[Valeh Hajiyev]

This commit addresses the current limitation in the `PriorityQueue` implementation, which lacks a constructor to efficiently create a priority queue with a custom comparator and an existing collection. In order to create such a queue, we currently need to initialize a new queue with custom comparator, and after that populate the queue using `addAll()` method, which in the background calls `add()` method (which takes `O(logn)` time) for each element of the collection (`n` times).  This is resulting in an overall time complexity of `O(nlogn)`. 


PriorityQueue<String> pq = new PriorityQueue<>(customComparator);
pq.addAll(existingCollection);


The pull request introduces a new constructor to streamline this process and reduce the time complexity to `O(n)`.  If you create the queue above using the new constructor, the contents of the collection will be copied (which takes `O(n)` time) and then later  `heapify()` operation (Floyd's algorithm) will be called once (another `O(n)` time). Overall the operation will be reduced from `O(nlogn)` to `O(2n)` -> `O(n)` time.


PriorityQueue<String> pq = new PriorityQueue<>(existingCollection, customComparator);

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Commit messages:
 - fix styling
 - Introduce constructor for PriorityQueue with existing collection and custom comparator

Changes: https://git.openjdk.org/jdk/pull/17045/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=17045&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-6356745
  Stats: 19 lines in 1 file changed: 19 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/17045.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/17045/head:pull/17045

PR: https://git.openjdk.org/jdk/pull/17045