Fix comment (old filename '.lhs') in libraries/

[skip ci]

There are some old file names (*.lhs) at comments.
(I'm fixing to read source code by newcomers.)

* libraries/base/GHC/Base.hs
  - compiler/deSugar/DsListComp.lhs
  - PrelRules.lhs x2
  - Base.lhs

* libraries/base/GHC/IO.hs
  - PrimOp.lhs
  - GHC.IO.lhs
  - GHC.Exception.lhs

* libraries/base/GHC/Real.hs
  - compiler/prelude/PrelRules.lhs

* libraries/ghc-prim/GHC/Magic.hs
  - MkId.lhs x2

Reviewers: austin, hvr, bgamari

Reviewed By: bgamari

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D3060

4 files changed, 10 insertions, 10 deletions

diff --git a/libraries/base/GHC/Base.hs b/libraries/base/GHC/Base.hs
index 25c78b2f22..2863ea71ac 100644
--- a/libraries/base/GHC/Base.hs
+++ b/libraries/base/GHC/Base.hs
@@ -261,7 +261,7 @@ mechanism to define mconcat and the Applicative and Monad instances for lists.
 We mark them INLINE because the inliner is not generally too keen to inline
 build forms such as the ones these desugar to without our insistence.  Defining
 these using list comprehensions instead of foldr has an additional potential
-benefit, as described in compiler/deSugar/DsListComp.lhs: if optimizations
+benefit, as described in compiler/deSugar/DsListComp.hs: if optimizations
 needed to make foldr/build forms efficient are turned off, we'll get reasonably
 efficient translations anyway.
 -}
@@ -991,7 +991,7 @@ eqString (c1:cs1) (c2:cs2) = c1 == c2 && cs1 `eqString` cs2
 eqString _        _        = False
 
 {-# RULES "eqString" (==) = eqString #-}
--- eqString also has a BuiltInRule in PrelRules.lhs:
+-- eqString also has a BuiltInRule in PrelRules.hs:
 --      eqString (unpackCString# (Lit s1)) (unpackCString# (Lit s2)) = s1==s2
 
 
@@ -1038,7 +1038,7 @@ id x                    =  x
 
 --      SLPJ: in 5.04 etc 'assert' is in GHC.Prim,
 --      but from Template Haskell onwards it's simply
---      defined here in Base.lhs
+--      defined here in Base.hs
 assert :: Bool -> a -> a
 assert _pred r = r
 
@@ -1249,7 +1249,7 @@ a `iShiftRL#` b | isTrue# (b >=# WORD_SIZE_IN_BITS#) = 0#
 "unpack-list"  [1]  forall a   . unpackFoldrCString# a (:) [] = unpackCString# a
 "unpack-append"     forall a n . unpackFoldrCString# a (:) n  = unpackAppendCString# a n
 
--- There's a built-in rule (in PrelRules.lhs) for
+-- There's a built-in rule (in PrelRules.hs) for
 --      unpackFoldr "foo" c (unpackFoldr "baz" c n)  =  unpackFoldr "foobaz" c n
 
   #-}
diff --git a/libraries/base/GHC/IO.hs b/libraries/base/GHC/IO.hs
index 52a333a273..0744e3a776 100644
--- a/libraries/base/GHC/IO.hs
+++ b/libraries/base/GHC/IO.hs
@@ -59,15 +59,15 @@ implement IO exceptions.
 NOTE: The IO representation is deeply wired in to various parts of the
 system.  The following list may or may not be exhaustive:
 
-Compiler  - types of various primitives in PrimOp.lhs
+Compiler  - types of various primitives in PrimOp.hs
 
 RTS       - forceIO (StgMiscClosures.hc)
           - catchzh_fast, (un)?blockAsyncExceptionszh_fast, raisezh_fast
             (Exceptions.hc)
           - raiseAsync (Schedule.c)
 
-Prelude   - GHC.IO.lhs, and several other places including
-            GHC.Exception.lhs.
+Prelude   - GHC.IO.hs, and several other places including
+            GHC.Exception.hs.
 
 Libraries - parts of hslibs/lang.
 
diff --git a/libraries/base/GHC/Real.hs b/libraries/base/GHC/Real.hs
index 39a7a9ddfd..17d56c6d8a 100644
--- a/libraries/base/GHC/Real.hs
+++ b/libraries/base/GHC/Real.hs
@@ -329,7 +329,7 @@ instance  Real Integer  where
 --
 -- Constant folding of quot, rem, div, mod, divMod and quotRem for
 -- Integer arguments depends crucially on inlining. Constant folding
--- rules defined in compiler/prelude/PrelRules.lhs trigger for
+-- rules defined in compiler/prelude/PrelRules.hs trigger for
 -- quotInteger, remInteger and so on. So if calls to quot, rem and so on
 -- were not inlined the rules would not fire. The rules would also not
 -- fire if calls to quotInteger and so on were inlined, but this does not
diff --git a/libraries/ghc-prim/GHC/Magic.hs b/libraries/ghc-prim/GHC/Magic.hs
index ecdffc5600..3dbda1dbd4 100644
--- a/libraries/ghc-prim/GHC/Magic.hs
+++ b/libraries/ghc-prim/GHC/Magic.hs
@@ -76,7 +76,7 @@ noinline x = x
 lazy :: a -> a
 lazy x = x
 -- Implementation note: its strictness and unfolding are over-ridden
--- by the definition in MkId.lhs; in both cases to nothing at all.
+-- by the definition in MkId.hs; in both cases to nothing at all.
 -- That way, 'lazy' does not get inlined, and the strictness analyser
 -- sees it as lazy.  Then the worker/wrapper phase inlines it.
 -- Result: happiness
@@ -97,7 +97,7 @@ oneShot :: forall (q :: RuntimeRep) (r :: RuntimeRep)
                   (a :: TYPE q) (b :: TYPE r).
            (a -> b) -> a -> b
 oneShot f = f
--- Implementation note: This is wired in in MkId.lhs, so the code here is
+-- Implementation note: This is wired in in MkId.hs, so the code here is
 -- mostly there to have a place for the documentation.
 
 -- | Apply a function to a 'State# RealWorld' token. When manually applying