[aarch64-port-dev ] RFR: 8149907: aarch64: use load/store pair instructions in call_stub

[Felix Yang]

Hi,

Please review the following webrev:
http://cr.openjdk.java.net/~fyang/8149907/webrev.00/

Jira issue: https://bugs.openjdk.java.net/browse/JDK-8149907

This patch make use of load/store pair instructions in call_stub
saving 24 load/store instructions.

Tested with jtreg hotspot & langtools.  Is it OK?

Thanks,
Felix.