JS: remove broken newIdents from JStg Monad

GHC.JS.JStg.Monad.newIdents was broken, resulting in duplicate
identifiers being generated in h$c1, h$c2, ... .

This change removes the broken newIdents.

compiler/GHC/JS/JStg/Monad.hs

@@ -40,7 +40,6 @@ module GHC.JS.JStg.Monad
   , JSM
   , withTag
   , newIdent
-  , newIdents
   , initJSM
   ) where
 
@@ -95,19 +94,6 @@ newIdent = do env <- get
 mk_ident :: FastString -> Unique -> Ident
 mk_ident t i = global (mconcat [t, "_", mkFastString (show i)])
 
-
-
--- | A special case optimization over @newIdent@. Given a number of @Ident@ to
--- generate, generate all of them at one time and update the state once rather
--- than n times.
-newIdents :: Int -> JSM [Ident]
-newIdents 0 = return []
-newIdents n = do env <- get
-                 let is  = take n (uniqsFromSupply $ ids env)
-                     tag = prefix env
-                 return $ fmap (mk_ident tag) is
-
-
 -- | Set the tag for @Ident@s for all remaining computations.
 tag_names :: FastString -> JSM ()
 tag_names tag = modify' (\env -> env {prefix = tag})

compiler/GHC/JS/Make.hs

@@ -149,6 +149,7 @@ import GHC.JS.JStg.Monad
 import GHC.JS.Transform
 
 import Control.Arrow ((***))
+import Control.Monad (replicateM)
 import Data.Tuple
 
 import qualified Data.Map as M
@@ -325,7 +326,7 @@ jFunctionSized
   -> ([JStgExpr] -> JSM JStgStat) -- ^ function body, input is locally unique generated variables
   -> JSM JStgStat
 jFunctionSized name arity body = do
-  func_args <- newIdents arity
+  func_args <- replicateM arity newIdent
   FuncStat name func_args <$> (body $ toJExpr <$> func_args)
 
 -- | Construct a top-level function subject to JS hoisting. Special case where