include wxchar.h from string.h in 2.8 compatibility mode to prevent lots of compilation errors

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@45688 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/string.h

@@ -2756,4 +2756,12 @@ inline wxWCharBuffer::wxWCharBuffer(const wxCStrData& cstr)
 {
 }
 
+#if WXWIN_COMPATIBILITY_2_8
+    // lot of code out there doesn't explicitly include wx/wxchar.h, but uses
+    // CRT wrappers that are now declared in wx/wxcrt.h and wx/wxcrtvararg.h,
+    // so let's include this header now that wxString is defined and it's safe
+    // to do it:
+    #include "wx/wxchar.h"
+#endif
+
 #endif  // _WX_WXSTRING_H_