Remove support for MetroWerks CodeWarrior compiler.

This compiler doesn't exist any more and was probably unsupported even in 2.8,
let alone 2.9, so remove all the __MWERKS__ tests to simplify things.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@71102 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/common/filefn.cpp

@@ -76,7 +76,7 @@
 
     // io.h is needed for _get_osfhandle()
     // Already included by filefn.h for many Windows compilers
-    #if defined __MWERKS__ || defined __CYGWIN__
+    #if defined __CYGWIN__
         #include <io.h>
     #endif
 #endif // __WINDOWS__
@@ -1191,8 +1191,7 @@ bool wxRemoveFile(const wxString& file)
  || defined(__BORLANDC__) \
  || defined(__WATCOMC__) \
  || defined(__DMC__) \
- || defined(__GNUWIN32__) \
- || (defined(__MWERKS__) && defined(__MSL__))
+ || defined(__GNUWIN32__)
     int res = wxRemove(file);
 #elif defined(__WXMAC__)
     int res = unlink(file.fn_str());