RFR: 8242325: Remove VIS version of medialib

[Philip Race]

Bug: https://bugs.openjdk.java.net/browse/JDK-8242325
Webrev : http://cr.openjdk.java.net/~prr/8242325/

With the impending removal of the Solaris SPARC port, there is even less 
point
than before to keeping around the VIS version of medialib, and versions of
the 2D rendering loops that call into it.

Since the library isn't loaded by default, things should still work as 
before.
Build still works - on SPARC and other platforms, and all headless 
client tests pass on Solaris.

-phil.