More

This makes more of the gcc spurious warning:

../../src/hb-null.hh:53:39: warning: enum constant in boolean context [-Wint-in-bool-context]

But not going to let that defeat correct code.  Type to switch to clang
as my main compiler...

src/hb-blob.hh

@@ -60,7 +60,7 @@ struct hb_blob_t
   template <typename Type>
   inline const Type* as (void) const
   {
-    return length < Type::min_size ? &Null(Type) : reinterpret_cast<const Type *> (data);
+    return length < hb_null_size<Type>::value ? &Null(Type) : reinterpret_cast<const Type *> (data);
   }
   inline hb_bytes_t as_bytes (void) const
   {