Quick compiler: disable GVN DO NOT MERGE

Disable global value numbering optimization for lmp (but
keep on for master).

b/16398693

Change-Id: I125c588c987a81db54a15da1eec9dee2b009956f
diff --git a/compiler/dex/frontend.cc b/compiler/dex/frontend.cc
index 3caefa2..2ba320f 100644
--- a/compiler/dex/frontend.cc
+++ b/compiler/dex/frontend.cc
@@ -47,7 +47,7 @@
   // (1 << kSuppressLoads) |
   // (1 << kNullCheckElimination) |
   // (1 << kClassInitCheckElimination) |
-  // (1 << kGlobalValueNumbering) |
+  (1 << kGlobalValueNumbering) |
   // (1 << kPromoteRegs) |
   // (1 << kTrackLiveTemps) |
   // (1 << kSafeOptimizations) |