RFR: AOT: jaotc should provide an option to specify the path to the platform linker

[Bob Vandette]

Please review this change to the jaotc tool which allows the user to specify the path to the
native toolchain linker required by AOT.

RFE:

https://bugs.openjdk.java.net/browse/JDK-8174863? <https://bugs.openjdk.java.net/browse/JDK-8174863?>

WEBREV:

http://cr.openjdk.java.net/~bobv/8174863/hotspot/webrev/ <http://cr.openjdk.java.net/~bobv/8174863/hotspot/webrev/>

Bob.