Fix readwrite00[12] on Windows

testsuite/tests/ghc-regress/lib/IO/readwrite001.hs

@@ -5,7 +5,7 @@ module Main(main) where
 import IO
 import Directory ( removeFile, doesFileExist )
 import Monad
-#ifdef i386_unknown_mingw32
+#ifdef mingw32_HOST_OS
 import GHC.Handle(hSetBinaryMode)
 #endif
 
@@ -13,7 +13,7 @@ main = do
   f <- doesFileExist "readwrite001.inout" 
   when f (removeFile "readwrite001.inout")
   hdl <- openFile "readwrite001.inout" ReadWriteMode
-#ifdef i386_unknown_mingw32
+#ifdef mingw32_HOST_OS
   hSetBinaryMode hdl True
 #endif
   hSetBuffering hdl LineBuffering

testsuite/tests/ghc-regress/lib/IO/readwrite002.hs

@@ -3,7 +3,7 @@
 import IO
 import Directory (removeFile, doesFileExist)
 import Monad
-#ifdef i386_unknown_mingw32
+#ifdef mingw32_HOST_OS
 import GHC.Handle(hSetBinaryMode)
 #endif
 
@@ -15,7 +15,7 @@ main = do
    f <- doesFileExist username
    when f (removeFile username)
    cd <- openFile username ReadWriteMode
-#ifdef i386_unknown_mingw32
+#ifdef mingw32_HOST_OS
    hSetBinaryMode cd True
 #endif
    hSetBuffering stdin NoBuffering