linking fix

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@8787 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/common/stream.cpp

@@ -627,6 +627,16 @@ wxStreamBase::~wxStreamBase()
 {
 }
 
+off_t wxStreamBase::OnSysSeek(off_t WXUNUSED(seek), wxSeekMode WXUNUSED(mode))
+{
+    return wxInvalidOffset;
+}
+
+off_t wxStreamBase::OnSysTell() const
+{
+    return wxInvalidOffset;
+}
+
 // ----------------------------------------------------------------------------
 // wxInputStream
 // ----------------------------------------------------------------------------