Make csharp-mode-map inherit from prog-mode-map

Author: mattiasb

csharp-mode.el

@@ -1448,6 +1448,7 @@ This regexp is assumed to not match any non-operator identifier."
     ("finally" "finally" c-electric-continued-statement 0)))
 
 (defvar csharp-mode-map (let ((map (c-make-inherited-keymap)))
+                          (set-keymap-parent map prog-mode-map)
                           ;; Add bindings which are only useful for C#
                           map)
   "Keymap used in ‘csharp-mode’ buffers.")