RFR - JDK-8175556 : Add support for android-arm target platform

[Bob Vandette]

Changes look fine with me.  It’s good to see Android improving its libc compatibility.

Bob.

> On Feb 23, 2017, at 10:34 AM, Gary Adams <gary.adams at oracle.com> wrote:
> 
> As a follow up to the recent openjdk arm sources moving into open repos,
> this set of changes enables building android-arm vm instead of the zero vm.
> 
> When the android support was initially added to the mobile/dev repos we
> required support for older android platforms. e.g. api level 19 for android 4.4
> devices. This update raises that baseline to api level 21 for android 5.0 and higher.
> 
>  JIRA: https://bugs.openjdk.java.net/browse/JDK-8175556
>  Webrev: http://cr.openjdk.java.net/~gadams/8175556/webrev.00/webrev/
> 
> I plan to push these changes on Mon Feb 27, if there are no objections.