RFR (S): [TESTBUG] Tests fails on ARM64 due to unknown hardware

[Sergei Kovalev]

Hello All,

Please review the following change:

Issue: https://bugs.openjdk.java.net/browse/JDK-8078834
Webrev: http://cr.openjdk.java.net/~skovalev/8078834/webrev.00

hotspot/test/test_env.sh needs to be update to recognize "aarch64" 
platform.

testing done: verified manually on ARM64 platform.

-- 
With best regards,
Sergei