Fix missing member initializers

This fixes the -Werror build with some combination of
warning flags.

llvm-svn: 274707

llvm/include/llvm/Support/OnDiskHashTable.h

@@ -325,7 +325,7 @@ public:
     Info *InfoObj;
 
   public:
-    iterator() : Data(nullptr), Len(0) {}
+    iterator() : Key(), Data(nullptr), Len(0), InfoObj(nullptr) {}
     iterator(const internal_key_type K, const unsigned char *D, offset_type L,
              Info *InfoObj)
         : Key(K), Data(D), Len(L), InfoObj(InfoObj) {}