RFR(XS): 8211207: AArch64: Fix build failure after JDK-8211029

[Pengfei Li (Arm Technology China)]

Hi,

The commit "8211029: Have a common set of enabled warnings for all native libraries" breaks AArch64 build.
We have several code warnings in AArch64 C1 and template table. And options "-Werror=c++11-compat" and "-Werror=switch" are turned on by this commit.
Error log can be found at JBS: https://bugs.openjdk.java.net/browse/JDK-8211207

Please help review this patch that fixed these warnings in AArch64 backend.
webrev: http://cr.openjdk.java.net/~njian/8211207/webrev.00/

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Thanks,
Pengfei