RFR: [XS] 8230485: add handling of aix tar in configure

[Baesken, Matthias]

Hello,  please review this small AIX related change .

I noticed that  configure does not recognize  AIX tar  correctly .   This leads  in the jdk/jdk AIX  - build   to a message :

checking what type of tar was found...
(without an info about the found tar )

Also the flag setting for aix tar is not correct .



Thanks, Matthias


Bug/webrev :

https://bugs.openjdk.java.net/browse/JDK-8230485

http://cr.openjdk.java.net/~mbaesken/webrevs/8230485.0/