ART: Add more ThreadOffset in Mir2Lir and backends

This duplicates all methods with ThreadOffset parameters, so that
both ThreadOffset<4> and ThreadOffset<8> can be handled. Dynamic
checks against the compilation unit's instruction set determine
which pointer size to use and therefore which methods to call.

Methods with unsupported pointer sizes should fatally fail, as
this indicates an issue during method selection.

Change-Id: Ifdb445b3732d3dc5e6a220db57374a55e91e1bf6
diff --git a/compiler/dex/quick/arm/utility_arm.cc b/compiler/dex/quick/arm/utility_arm.cc
index 1afd890..fe18ed9 100644
--- a/compiler/dex/quick/arm/utility_arm.cc
+++ b/compiler/dex/quick/arm/utility_arm.cc
@@ -1161,6 +1161,11 @@
   return NULL;
 }
 
+LIR* ArmMir2Lir::OpThreadMem(OpKind op, ThreadOffset<8> thread_offset) {
+  UNIMPLEMENTED(FATAL) << "Should not be called.";
+  return nullptr;
+}
+
 LIR* ArmMir2Lir::OpMem(OpKind op, RegStorage r_base, int disp) {
   LOG(FATAL) << "Unexpected use of OpMem for Arm";
   return NULL;