RFR: JDK-8147426 - Missing definition for JIMAGE_NOT_FOUND

[Jim Laskey (Oracle)]

JIMAGE_NOT_FOUND was defined in the hotspot jimage.hpp header but not in the jdk jimage.hpp header.  Brought the headers in line.

http://cr.openjdk.java.net/~jlaskey/8147426/webrev/index.html <http://cr.openjdk.java.net/~jlaskey/8147426/webrev/index.html>
https://bugs.openjdk.java.net/browse/JDK-8147426 <https://bugs.openjdk.java.net/browse/JDK-8147426>