RFR: 8374755: ML-KEM's 12-bit decompression uses incorrect assertions

[Ferenc Rakoczi]

The preconditions for the aarch64 and the AVX-512 intrinsic implementations of the implKyber12To16() method of com.sun.crypto.provider.ML_KEM are different and the AVX-512 one has stricter preconditions on the input, which was not recorded in the assert() before calling the function (although they were satisfied by all calling code). Now the assert() is corrected, and with these preconditions, the aarch64 implementation is simplified.

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Commit messages:
 - 8374755: ML-KEM's 12-bit decompression uses incorrect assertions

Changes: https://git.openjdk.org/jdk/pull/29141/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=29141&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8374755
  Stats: 90 lines in 2 files changed: 4 ins; 73 del; 13 mod
  Patch: https://git.openjdk.org/jdk/pull/29141.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/29141/head:pull/29141

PR: https://git.openjdk.org/jdk/pull/29141