Add wxFileName::SetPermissions().

This is a simple wrapper for the POSIX chmod().

Closes #12951.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@74639 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

interface/wx/filename.h

@@ -1256,6 +1256,23 @@ public:
      */
     void SetPath(const wxString& path, wxPathFormat format = wxPATH_NATIVE);
 
+    /**
+        Sets permissions for this file or directory.
+
+        @param permissions
+            The new permissions: this should be a combination of
+            ::wxPosixPermissions enum elements.
+
+        @since 2.9.6
+
+        @note If this is a symbolic link and it should not be followed
+              this call will fail.
+
+        @return @true on success, @false if an error occurred (for example,
+                the file doesn't exist).
+    */
+    bool SetPermissions(int permissions)
+
     /**
         Sets the file creation and last access/modification times (any of the pointers
         may be @NULL).