[vectorIntrinsics] RFR: Remove `byte[]` and `ByteBuffer` access methods. [v2]

[Paul Sandoz]

> Removes `byte[]` and `ByteBuffer` vector access methods.
> 
> Fixes performance issue with the fallback implementation of `MemorySegment` accessors (the `ValueLayout` passed to the scalar accessors needs to be constant).

Paul Sandoz has updated the pull request incrementally with one additional commit since the last revision:

  Sync tests with update to template

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

Changes:
  - all: https://git.openjdk.java.net/panama-vector/pull/190/files
  - new: https://git.openjdk.java.net/panama-vector/pull/190/files/dcf0eea3..3202fdb1

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=panama-vector&pr=190&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=panama-vector&pr=190&range=00-01

  Stats: 150 lines in 30 files changed: 60 ins; 60 del; 30 mod
  Patch: https://git.openjdk.java.net/panama-vector/pull/190.diff
  Fetch: git fetch https://git.openjdk.java.net/panama-vector pull/190/head:pull/190

PR: https://git.openjdk.java.net/panama-vector/pull/190