RFR: JDK-8196724: Change macosx deployment target to 10.9

Wed Apr 4 18:30:08 UTC 2018

This patch changes the values for the macosx version min and max 
settings from 10.7 to 10.9. It also changes the stdlib from libstdc++ to 
libc++ (explicitly for Hotspot and implicitly everywhere else). This 
change is necessary to keep up with newer toolchain versions on Macosx 
where using the old and no longer maintained libstdc++ has been 
deprecated. This is done in preparation for bumping the preferred Xcode 
version used for builds at Oracle.

The switch has been tested for both Hotspot and client.

The switch triggered some new deprecation warnings which have been 
silenced and followup bugs have been filed on the concerned team.

Bug: https://bugs.openjdk.java.net/browse/JDK-8196724

Webrev: http://cr.openjdk.java.net/~erikj/8196724/webrev.01/index.html

/Erik