[11u] RFR 8254717: isAssignableFrom checks in KeyFactorySpi.engineGetKeySpec appear to be backwards

[Luo, Ziyi]

Hi,

May I have a review of this backport to 11u:

JBS: https://bugs.openjdk.java.net/browse/JDK-8254717
Webrev: http://cr.openjdk.java.net/~luoziyi/8254717/webrev.00

This is almost a clean backport except a missing class 
sun.security.ec.ed.EdDSAKeyFactory. The class is introduced in JDK-8166597: 
Crypto support for the EdDSA Signature Algorithm, a new feature in JDK15.

IMPORTANT: This patch introduces a regression in JCK17. We addressed it in 
JDK-8263404 and I prepared the backport as well (I have another RFR for 
it):

http://cr.openjdk.java.net/~luoziyi/8263404/webrev.00/

Upon both backports are ready for merging, please merge 8254717 first.

Tests: jtreg jdk:tier1/2

Thanks,
Ziyi