Make pnacl-bccompress add abbreviations for obvious constants.

include/llvm/Bitcode/NaCl/NaClCompressCodeDist.h

Index: include/llvm/Bitcode/NaCl/NaClCompressCodeDist.h
diff --git a/include/llvm/Bitcode/NaCl/NaClCompressCodeDist.h b/include/llvm/Bitcode/NaCl/NaClCompressCodeDist.h
index ab9202b32b96cf2125e42661cff98f8c485834bb..71b1775482afd45943d8f40cf74307f67a49fa94 100644
--- a/include/llvm/Bitcode/NaCl/NaClCompressCodeDist.h
+++ b/include/llvm/Bitcode/NaCl/NaClCompressCodeDist.h
@@ -42,8 +42,8 @@ public:
   virtual const SmallVectorImpl<NaClBitcodeDist*> *
   GetNestedDistributions() const;
 
-  NaClBitcodeDist *GetSizeDist() {
-    return &SizeDist;
+  NaClBitcodeDist &GetSizeDist() {
+    return SizeDist;
   }
 
   /// The sentinel used to generate instances of this in