Class initialization check elimination.

Also, move null check elimination temporaries to the
ScopedArenaAllocator and reuse the same variables in the
class initialization check elimination.

Change-Id: Ic746f95427065506fa6016d4931e4cb8b34937af
diff --git a/compiler/dex/frontend.h b/compiler/dex/frontend.h
index 22a7b8c..37c85b1 100644
--- a/compiler/dex/frontend.h
+++ b/compiler/dex/frontend.h
@@ -44,6 +44,7 @@
   kLoadHoisting,
   kSuppressLoads,
   kNullCheckElimination,
+  kClassInitCheckElimination,
   kPromoteRegs,
   kTrackLiveTemps,
   kSafeOptimizations,