RFR: 8186958: Need method to create pre-sized HashMap [v15]

[XenoAmess]

> 8186958: Need method to create pre-sized HashMap

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

 - Add apiNote to appropriate constructors of HM, LHM, and WHM.
 - Add test cases for static factory methods.
 - Minor adjustment to test cases of WhiteBoxResizeTest

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Changes:
  - all: https://git.openjdk.java.net/jdk/pull/7928/files
  - new: https://git.openjdk.java.net/jdk/pull/7928/files/7adc89c1..ab8fbb83

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=7928&range=14
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=7928&range=13-14

  Stats: 85 lines in 4 files changed: 77 ins; 1 del; 7 mod
  Patch: https://git.openjdk.java.net/jdk/pull/7928.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/7928/head:pull/7928

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