FRF: 8250675: Vector API crashes on AVX512 machines with assert(eval_map.contains(n)) failed: absent

[jiefu(傅杰)]

Hi all,

Please review the following patch which fixes some Vector API crashes on AVX512 machines.

JBS:    https://bugs.openjdk.java.net/browse/JDK-8250675
Webrev: http://cr.openjdk.java.net/~jiefu/8250675/webrev.00/

Testing:
  - jdk/incubator/vector all passed on AVX512 machines
  - tier1 on Linux/x64

Thanks a lot.
Best regards,
Jie