RFR: 8145132: Initial updates for ios x86_64 mobile/dev builds.

[Gary Adams]

Here's the initial upload of changes that provides support for the ios 
and android ports
for the mobile/dev repos. While there have been some preliminary reviews 
of the code,
there is still more work required before we will look for more thorough 
reviews
and an integration to mobile/jdk9 repos.

   Issue: https://bugs.openjdk.java.net/browse/JDK-8145132
   Webrev: http://cr.openjdk.java.net/~gadams/8145132/webrev.00/


Here's a simple configure script to generate a ios-x86_64 build for use
with the iphone simulator. (uses homebrew 64 bit freetype from pkgconfig)

export JAVA_HOME=`/usr/libexec/java_home -v 1.8`
export PATH=$JAVA_HOME/bin:~/homebrew/bin:$PATH

bash ../../configure \
     --openjdk-target=x86_64-macos-ios \
     --with-boot-jdk=$JAVA_HOME \
     --disable-warnings-as-errors \
     --disable-headful \
     --enable-static-build=yes \
     --with-jvm-variants=minimal1


Also, tested with i586-macos-ios target for 32 bit
with a locally built --with-freetype 2.6.2.