8151340: aarch64: prefetch the destination word for write prior to ldxr/stxr loops. Summary: aarch64: add prefetch for write prior to ldxr/stxr loops. Reviewed-by: aph Contributed-by: felix.yang@linaro.org

^build/
^dist/
nbproject/private/
^webrev
^.hgtip
^.bridge2
^.jib/
.DS_Store
.metadata/
.recommenders/