RFR(S): AArch64: NMT detail stack trace cleanup

[dmitry.samersov]

Everybody,

Please, review a minimal, aarch64 only patch that makes aarch64 behavior
similar to x86 one.

http://cr.openjdk.java.net/~dsamersoff/JDK-8163011/aarch64_only/webrev.01/

This patch is not a replacement for a larger refactoring I proposed
early, but the refactoring requires significant effort to test it on
different platforms, so I plan to file a separate CR and address it when
possible.

-Dmitry