[aarch64-port-dev ] RFR: 8150394: aarch64: add support for 8.1 LSE CAS instructions

[Andrew Haley]

Here's what I've got, merging my changes for VarHandles with yours
for LSE CAS:

http://cr.openjdk.java.net/~aph/aarch64-lse-cas/

Please test it.

Thanks,

Andrew.