RFR: JDK-8046474 Source changes needed to build JDK 9 with new platforms and compilers on Solaris and Linux

[Tim Bell]

Please review in preparation for updating to new platforms and compilers 
on Solaris and Linux:

This is a minor change to the make/jprt.properties and 
hotspot/make/jprt.properties files.

Bug report:

https://bugs.openjdk.java.net/browse/JDK-8046474

Webrev:

http://cr.openjdk.java.net/~tbell/8046474/

Thank you-

Tim