Test JCE ChaCha/Poly
Java 20 adds intrinsic support for AVX/AVX2/AVX512 in JCE ChaCha/Poly (been in JCE since java 11). We do not use JCE ChaCha/Poly now; we have thin wrappers around the Noise code. Test speed on various JREs and hardware and data lengths.
Note that this open bug says lengths <= 512 are slower on AVX512 then AVX2: https://bugs.openjdk.org/browse/JDK-8302007
Depending on results we could switch or do it contingent on CPUID info and length as we do for AES. Or for our data lengths it may not be worth it at all.