Only include <unistd.h> under Unix in wxGTK code.

Also remove the inclusions of some Unix-specific headers that were not needed
at all.

Closes #14048.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@70704 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

demos/forty/scorefil.cpp

@@ -20,11 +20,6 @@
 #include "wx/wx.h"
 #endif
 
-#ifdef __WXGTK__
-#include <unistd.h>
-#include <sys/stat.h>
-#include <fcntl.h>
-#endif
 #include "wx/textfile.h"
 #include "wx/config.h"
 #include "wx/fileconf.h"

src/gtk/dirdlg.cpp

@@ -31,7 +31,9 @@
 
 #include "wx/gtk/private.h"
 
+#ifdef __UNIX__
 #include <unistd.h> // chdir
+#endif
 
 //-----------------------------------------------------------------------------
 // "clicked" for OK-button

src/gtk/filedlg.cpp

@@ -22,7 +22,9 @@
 #include <gtk/gtk.h>
 #include "wx/gtk/private.h"
 
+#ifdef __UNIX__
 #include <unistd.h> // chdir
+#endif
 
 #include "wx/filename.h" // wxFilename
 #include "wx/tokenzr.h" // wxStringTokenizer

src/gtk/filepicker.cpp

@@ -144,7 +144,9 @@ void wxFileButton::SetInitialDirectory(const wxString& dir)
 
 #if wxUSE_DIRPICKERCTRL && defined(__WXGTK26__)
 
+#ifdef __UNIX__
 #include <unistd.h> // chdir
+#endif
 
 //-----------------------------------------------------------------------------
 // "current-folder-changed"

src/gtk/utilsgtk.cpp

@@ -45,8 +45,9 @@
 #include <string.h>
 #include <sys/stat.h>
 #include <sys/types.h>
-#include <sys/wait.h>   // for WNOHANG
+#ifdef __UNIX__
 #include <unistd.h>
+#endif
 
 #if wxUSE_DETECT_SM
     #include <X11/SM/SMlib.h>