hg: shenandoah/jdk10/hotspot: Fix, improve and refactor matrix barrier on AAarch64.

[roman at kennke.org]

Changeset: 4c74a522ee99
Author:    rkennke
Date:      2017-09-14 11:09 -0400
URL:       http://hg.openjdk.java.net/shenandoah/jdk10/hotspot/rev/4c74a522ee99

Fix, improve and refactor matrix barrier on AAarch64.

! src/cpu/aarch64/vm/macroAssembler_aarch64.cpp
! src/cpu/aarch64/vm/templateTable_aarch64.cpp