RFR: JDK-8289551: Conversions between bit representations of half precision values and floats [v5]

[Joe Darcy]

> Initial implementation.

Joe Darcy has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains 20 additional commits since the last revision:

 - Method rename.
 - Merge branch 'master' into JDK-8289551
 - Respond to review feedback; improve tests.
 - Add NaN test.
 - Preserve NaN sign bit.
 - Respond to review feedback.
 - Correct carry-out bug; add full binade test.
 - Improve NaN significand fidelity; refine tests.
 - Partial implementation of review feedback; test refinement.
 - Merge branch 'master' into JDK-8289551
 - ... and 10 more: https://git.openjdk.org/jdk/compare/fc62ffae...9b060185

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/9422/files
  - new: https://git.openjdk.org/jdk/pull/9422/files/a30daf2f..9b060185

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=9422&range=04
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=9422&range=03-04

  Stats: 11169 lines in 334 files changed: 7634 ins; 2341 del; 1194 mod
  Patch: https://git.openjdk.org/jdk/pull/9422.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/9422/head:pull/9422

PR: https://git.openjdk.org/jdk/pull/9422