RFR: 8312425: [vectorapi] AArch64: Optimize vector math operations with SLEEF [v2]

[Hamlin Li]

> Hi,
> Can you help to review the patch?
> This pr is based on previous work and discussion in [pr 16234](https://github.com/openjdk/jdk/pull/16234), [pr 18294](https://github.com/openjdk/jdk/pull/18294).
> 
> Compared with previous prs, the major change in this pr is to integrate the source of sleef (for the steps, please check `src/jdk.incubator.vector/linux/native/libvectormath/README`), rather than depends on external sleef things (header or lib) at build or run time.
> Besides of this change, also modify the previous changes accordingly, e.g. remove some uncessary files or changes especially in make dir of jdk.
> 
> Besides of the code changes, one important task is to handle the legal process.
> 
> Thanks!

Hamlin Li has updated the pull request incrementally with two additional commits since the last revision:

 - disable unused-function warnings; add log msg
 - minor

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/18605/files
  - new: https://git.openjdk.org/jdk/pull/18605/files/3ab4795d..34529ff1

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=18605&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=18605&range=00-01

  Stats: 8 lines in 4 files changed: 5 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/18605.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/18605/head:pull/18605

PR: https://git.openjdk.org/jdk/pull/18605