Remove unused instance using Orphans

Author: jneira

plugins/tactics/src/Ide/Plugin/Tactic/Types.hs

@@ -32,6 +32,7 @@ import Data.Map (Map)
 import Data.Set (Set)
 import Data.Tree
 import Development.IDE.GHC.Compat hiding (Node)
+import Development.IDE.GHC.Orphans ()
 import Development.IDE.Types.Location
 import GHC.Generics
 import Ide.Plugin.Tactic.Debug
@@ -65,9 +66,6 @@ instance Show Var where
 instance Show TCvSubst where
   show  = unsafeRender
 
-instance {-# OVERLAPPING #-} Show (LHsExpr GhcPs) where
-  show  = unsafeRender
-
 instance Show DataCon where
   show  = unsafeRender