Merge #69: conditionally derive Ord

34e9d4c conditionally derive Ord (Riccardo Casatta)

Pull request description:

  Otherwise in fuzzing configuration there is a double impl

  Noticed the error in rust-elements CI

ACKs for top commit:
  apoelstra:
    ACK 34e9d4c

Tree-SHA512: 4a2651229cdf6ff82986ec7e821702045735e709cec1cb067cfcb3fcd179d7100a51cd865251363f2279c49d43e083024cb1357cb25f92f2b28940bbf2af8944

Author: apoelstra

secp256k1-zkp-sys/src/zkp.rs

@@ -533,7 +533,8 @@ impl From<Tag> for [u8; 32] {
 
 // TODO: Replace this with ffi::PublicKey?
 #[repr(C)]
-#[derive(Copy, Clone, PartialOrd, Ord)]
+#[derive(Copy, Clone)]
+#[cfg_attr(not(fuzzing), derive(Ord, PartialOrd))]
 pub struct PedersenCommitment([c_uchar; 64]);
 impl_array_newtype!(PedersenCommitment, c_uchar, 64);
 impl_raw_debug!(PedersenCommitment);