RFR: 8310843: Reimplement ByteArray and ByteArrayLittleEndian with Unsafe [v2]

[Glavo]

> `ByteArray` and `ByteArrayLittleEndian` are very useful tool classes that can be used in many places to performance tuning.
> 
> Currently they are implemented by `VarHandle`, so using them may have some impact on startup time.
> 
> This PR reimplements them using `Unsafe`, which reduces the impact on startup time.

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

  update tests

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/14636/files
  - new: https://git.openjdk.org/jdk/pull/14636/files/6b14fa7e..8a507b9a

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=14636&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=14636&range=00-01

  Stats: 400 lines in 1 file changed: 305 ins; 19 del; 76 mod
  Patch: https://git.openjdk.org/jdk/pull/14636.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/14636/head:pull/14636

PR: https://git.openjdk.org/jdk/pull/14636