Add wxText{Input,Output}Stream::Get{Input,Output}Stream() methods.

These methods simply return the underlying low-level stream.

See #10807.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@67286 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

interface/wx/txtstrm.h

@@ -73,6 +73,13 @@ public:
     */
     ~wxTextInputStream();
 
+    /**
+        Returns a pointer to the underlying input stream object.
+
+        @since 2.9.2
+    */
+    const wxInputStream& GetInputStream() const;
+
     /**
         Reads a character, returns 0 if there are no more characters in the
         stream.
@@ -252,6 +259,13 @@ public:
      */
     void Flush();
 
+    /**
+        Returns a pointer to the underlying output stream object.
+
+        @since 2.9.2
+    */
+    const wxOutputStream& GetOutputStream() const;
+
     /**
         Returns the end-of-line mode. One of ::wxEOL_DOS, ::wxEOL_MAC and
         ::wxEOL_UNIX.