Add wxNOEXCEPT and use it for std::streambuf-derived classes.

This fixes warnings from Intel compiler about overriding function using a
different exception specification than the base one and also incidentally
provides a handy macro that can be useful in other situations.

Closes #14826.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@72978 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/generic/spinctlg.cpp

@@ -77,7 +77,7 @@ public:
         SetSizeHints(wxDefaultCoord, wxDefaultCoord);
     }
 
-    virtual ~wxSpinCtrlTextGeneric()
+    virtual ~wxSpinCtrlTextGeneric() wxNOEXCEPT
     {
         // MSW sends extra kill focus event on destroy
         if (m_spin)