Fix a DCHECK failure in Arm64RelativePatcher with read barrier.

We could encounter an add immediate with
LinkerPatch::Type::kDexCacheArray for the
HLoadString::LoadKind::kDexCachePcRelative case of VisitLoadString if
the non-baker read barrier is enabled.

Bug: 28249352
Bug: 12687968
Change-Id: I226bea26f6a614cfabb0307805de7cedb3b54a7f
1 file changed