[OpenJDK 2D-Dev] RFR: JDK-8200793: Fix new compilation errors with Xcode 9.2 and deployment target 10.9

[Erik Joelsson]

After bumping the deployment target to 10.9, a few more compilation 
errors were triggered with Xcode 9.2 in deploy and libt2k.

Deploy fix looked trivial, but will soon be void anyway. In libt2k I 
simply disabled the warning as the source looks like something from 
upstream. Phil, do you think you will want to address this in a separate 
bug?

Bug: https://bugs.openjdk.java.net/browse/JDK-8200793

Webrev: http://javaweb.us.oracle.com/~ejoelsso/webrev/8200793/webrev.01/

/Erik