Revert "Revert "ART: Reference.getReferent intrinsic for x86 and x86_64""

This reverts commit 0997d24e67d78f2146ebae2888eda0d7d254789a.

ART_HEAP_POISONING=true mode is fixed.

Change-Id: I83f6d5c101ea6a86802753f81b3e4348a263fb21
Signed-off-by: Serguei Katkov <serguei.i.katkov@intel.com>
diff --git a/compiler/optimizing/code_generator.h b/compiler/optimizing/code_generator.h
index 6e75e3b..82a54d2 100644
--- a/compiler/optimizing/code_generator.h
+++ b/compiler/optimizing/code_generator.h
@@ -469,6 +469,9 @@
 
   virtual void GenerateNop() = 0;
 
+  uint32_t GetReferenceSlowFlagOffset() const;
+  uint32_t GetReferenceDisableFlagOffset() const;
+
  protected:
   // Method patch info used for recording locations of required linker patches and
   // target methods. The target method can be used for various purposes, whether for