RFR: 8019470 "Changes needed to compile JDK8 on MacOS with clang compiler"

[Tim Bell]

Hello everyone-

This is a small set of changes to switch from gcc to clang when building 
on MacOS, and also enable building on MacOS 8.x

Here is the bug report:

http://bugs.sun.com/view_bug.do?bug_id=8019470

Here are the webrevs:

Hotspot only:

   http://cr.openjdk.java.net/~tbell/8019470/hotspot/webrev.00/

All of the changes:

   http://cr.openjdk.java.net/~tbell/8019470/webrev.00/

Thanks in advance.

Tim