Migrate from using Unsafe to FFM's MemorySegment API for allocating and setting native memory. This code is used by Metal, OpenGL and D3D, so I manually tested SwingSet2 and J2Demo as well as running all the usual tests. I also did some micro-benchmarking on the performance of Unsafe vs MemorySegment. The performance of either is more than sufficient for us .. ie they could be 10x slower and we wouldn't even notice. But they are in the same ballpark, and if one or the other is clearly faster it is the new FFM code.
------------- Commit messages: - 8337237 Changes: https://git.openjdk.org/jdk/pull/20339/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=20339&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8337237 Stats: 67 lines in 1 file changed: 4 ins; 4 del; 59 mod Patch: https://git.openjdk.org/jdk/pull/20339.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/20339/head:pull/20339 PR: https://git.openjdk.org/jdk/pull/20339
