attempt compat. with GHC 9.x

pepeiborra · pepeiborra · commit 78f34b27cf6d · 2021-07-27T11:44:01.000+01:00
diff --git a/ghcide/src/Development/IDE/GHC/Orphans.hs b/ghcide/src/Development/IDE/GHC/Orphans.hs
@@ -51,6 +51,7 @@ instance Hashable GhcPlugins.InstalledUnitId where
   hashWithSalt salt = hashWithSalt salt . installedUnitIdString
 #else
 instance Show InstalledUnitId where show = prettyPrint
+deriving instance Ord SrcSpan
 #endif
 
 instance NFData SB.StringBuffer where rnf = rwhnf
