[vectorIntrinsics+fp16] RFR: Merge panama-vector:vectorIntrinsics

[Smita Kamath]

Resolved merge conflicts in 

src/jdk.incubator.vector/share/classes/jdk/incubator/vector/AbstractVector.java
src/jdk.incubator.vector/share/classes/jdk/incubator/vector/X-Vector.java.template

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

Commit messages:
 - Merge panama-vector:vectorIntrinsics
 - Add @since 19 tags
 - Merge panama-vector:master
 - 8285696: AlgorithmConstraints:permits not throwing IllegalArgumentException when 'alg'  is null
 - 8285493: ECC calculation error
 - 8284910: Buffer clean in PasswordCallback
 - 8285683: Missing @ since 11 in java.security.spec.MGF1ParameterSpec fields
 - 8285756: clean up use of bad arguments for `@clean` in langtools tests
 - 8285032: vmTestbase/nsk/jdi/EventSet/suspendPolicy/suspendpolicy008/ fails with "eventSet.suspendPolicy() != policyExpected"
 - 8285658: Fix two typos in the spec of j.u.random.RandomGenerator
 - ... and 2533 more: https://git.openjdk.org/panama-vector/compare/6b7b1070...755d749d

The webrevs contain the adjustments done while merging with regards to each parent branch:
 - vectorIntrinsics+fp16: https://webrevs.openjdk.org/?repo=panama-vector&pr=203&range=00.0
 - panama-vector:vectorIntrinsics: https://webrevs.openjdk.org/?repo=panama-vector&pr=203&range=00.1

Changes: https://git.openjdk.org/panama-vector/pull/203/files
  Stats: 1675548 lines in 9535 files changed: 960995 ins; 630162 del; 84391 mod
  Patch: https://git.openjdk.org/panama-vector/pull/203.diff
  Fetch: git fetch https://git.openjdk.org/panama-vector pull/203/head:pull/203

PR: https://git.openjdk.org/panama-vector/pull/203