RFR: 8249612 Remove unused ISNANF and ISNAND from jdk_util_md.h

[Alexander Scherbatiy]

Hello,

Could you review a simple clean up of jdk_util_md.h files:
   Bug: https://bugs.openjdk.java.net/browse/JDK-8249612
   Fix: http://cr.openjdk.java.net/~alexsch/8249612/webrev.00

JDK-8001334 [1] defines ISNANF and ISNAND in jdk_util_md.h.
JDK-8199424 [2] removes ISNANF and ISNAND usage.
ISNANF and ISNAND are not used any more in JDK code.
The proposed fix removes ISNANF and ISNAND definition from jdk_util_md.h.

[1] https://hg.openjdk.java.net/jdk/jdk/rev/e269be167fae
[2] https://hg.openjdk.java.net/jdk/jdk/rev/da8673f61e94

Thanks,
Alexander.