RFR(S) 8248660: AArch64: Use MSVC built-ins where applicable

[Monica Beckwith]

Hello all,

We are looking at utilizing MSVC built-ins as applicable. Please review the following:

JBS: https://bugs.openjdk.java.net/browse/JDK-8248660
Webrev: http://cr.openjdk.java.net/~mbeckwit/8248660/webrev.00/

Regards,
Monica