[vectorIntrinsics+fp16] RFR: [vectorIntrinsics+fp16] Fix for failing HalfFloat base test.

[Jatin Bhateja]

- Create DummyVector backed by short[] arrays for HalffloatSpecies till Halffloat becomes a value type.

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Commit messages:
 - Fix for failing HalfFloat base test.
 - Fixed space and tabs in code
 - FP16 Java support

Changes: https://git.openjdk.java.net/panama-vector/pull/172/files
 Webrev: https://webrevs.openjdk.java.net/?repo=panama-vector&pr=172&range=00
  Stats: 9583 lines in 22 files changed: 9466 ins; 8 del; 109 mod
  Patch: https://git.openjdk.java.net/panama-vector/pull/172.diff
  Fetch: git fetch https://git.openjdk.java.net/panama-vector pull/172/head:pull/172

PR: https://git.openjdk.java.net/panama-vector/pull/172