[aarch64-port-dev ] RFR(trivial): 8221220 AArch64: Add StoreStore membar explicitly for Volatile Writes in TemplateTable

[Patrick Zhang OS]

Hi,

This is a simple patch to make the barriers (used for volatile writes in TemplateTable::fast_storefield and TemplateTable::putfield_or_static) more *self-documented* than before. See more details in JIRA please.

JBS: https://bugs.openjdk.java.net/browse/JDK-8221220
Webrev (jdk/jdk): http://cr.openjdk.java.net/~qpzhang/8221220/webrev.00/
Webrev (aarch64-port/jdk8u-shenandoah/hotspot) http://cr.openjdk.java.net/~qpzhang/8221220/webrev.00.jdk8u/
Tests: no impact to practical functions in theory, ran jcstress as sanity checking, no regression found.

Regards
Patrick