[JDK-8312425](https://bugs.openjdk.org/browse/JDK-8312425) is looking to optimize vector math operations by leveraging the SLEEF library. For legal reasons the actual contribution of the SLEEF files needs to be handled separately.
This is a new attempt at solving [JDK-8329816](https://bugs.openjdk.org/browse/JDK-8329816); the original attempt is here: https://github.com/openjdk/jdk/pull/19185. This PR is based on the discussions on how to move forward that was held in that original PR. ------------- Commit messages: - Expand tabs to 8 spaces to make jcheck happy - Add generated sources for riscv64 - Remove executable bit - Add generated sources for aarch64 - Add build support for updating sleef sources - Add README - Add sleef license in legal - * Add source of libsleef 3.6.1 Changes: https://git.openjdk.org/jdk/pull/20781/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=20781&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8329816 Stats: 120301 lines in 175 files changed: 120301 ins; 0 del; 0 mod Patch: https://git.openjdk.org/jdk/pull/20781.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/20781/head:pull/20781 PR: https://git.openjdk.org/jdk/pull/20781
