update rust toolchain

It comes with a bunch of new lints (yay!) so I fixed them all so CI will
keep working.

Also apparently something about linking changed because I had to change
the checks for deciding the linker flags for static x86_64 builds to
keep working.

src/service/pdu.rs

@@ -385,7 +385,7 @@ impl PartialEq for PduEvent {
 }
 impl PartialOrd for PduEvent {
     fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
-        self.event_id.partial_cmp(&other.event_id)
+        Some(self.cmp(other))
     }
 }
 impl Ord for PduEvent {