RFR: 8284780: Need methods to create pre-sized HashSet and LinkedHashSet [v12]

[XenoAmess]

> as title.

XenoAmess has updated the pull request incrementally with two additional commits since the last revision:

 - add 8284780 to test
 - redo the tests

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/8302/files
  - new: https://git.openjdk.java.net/jdk/pull/8302/files/4ec6ba9f..df5a8512

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=8302&range=11
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=8302&range=10-11

  Stats: 92 lines in 1 file changed: 65 ins; 16 del; 11 mod
  Patch: https://git.openjdk.java.net/jdk/pull/8302.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/8302/head:pull/8302

PR: https://git.openjdk.java.net/jdk/pull/8302