RFR:8246051:[AArch64]SIGBUS by unaligned Unsafe compare_and_swap

[Wang Zhuo(Zhuoren)]

Hi, 
I found that on aarch64, SIGBUS happens when Unsafe compareAndSwapLong and compareAndSwapInt were used to access unaligned mem address in interpreter mode. In compiled code, InternalError will be thrown. We should fix the crash and throw InternalError in interpreter too.
Please help review this patch. 

BUG: https://bugs.openjdk.java.net/browse/JDK-8246051
CR: http://cr.openjdk.java.net/~wzhuo/8246051/webrev.00/

Regards,
Zhuoren