Consider warning about longish JNI critical section for the byte[]-based API

[bbrehm]

The byte array based API does all the work in JNI critical sections (e.g.

zstd-jni/src/main/native/jni_fast_zstd.c

Line 488 in 9b39b59

void *dst_buff = (*env)->GetPrimitiveArrayCritical(env, dst, NULL);

).

This is liable to cause OOM crashes when using that with G1 GC without region pinning https://openjdk.org/jeps/423, i.e. in a runtime before java 22.

I think a warning in the docs would be appropriate.

Or one could allocate a temp buffer in the C world, and only hold the critical section for the time of a memcpy.

PS. some other background: https://shipilev.net/jvm/anatomy-quarks/9-jni-critical-gclocker/