nativeGen: Use plusUFMList instead of foldr

compiler/nativeGen/AsmCodeGen.hs

@@ -929,7 +929,7 @@ generateJumpTables ncgImpl xs = concatMap f xs
 
 shortcutBranches
         :: DynFlags
-    -> NcgImpl statics instr jumpDest
+        -> NcgImpl statics instr jumpDest
         -> [NatCmmDecl statics instr]
         -> [NatCmmDecl statics instr]
 
@@ -938,7 +938,7 @@ shortcutBranches dflags ncgImpl tops
   | otherwise           = map (apply_mapping ncgImpl mapping) tops'
   where
     (tops', mappings) = mapAndUnzip (build_mapping ncgImpl) tops
-    mapping = foldr plusUFM emptyUFM mappings
+    mapping = plusUFMList mappings
 
 build_mapping :: NcgImpl statics instr jumpDest
               -> GenCmmDecl d (LabelMap t) (ListGraph instr)