Ensure that we define bool before using it for variables

It would have been better to hook into the fragment machinery, but for now do
it directly to make sure the generated code compiles.

Source/Modules/c.cxx

@@ -1247,6 +1247,11 @@ ready:
 
 	  if (!SwigType_isbuiltin(btype))
 	    return NIL;
+
+	  // Final complication: define bool if it is used here.
+	  if (Cmp(btype, "bool") == 0) {
+	    Printv(f_wrappers_types, "#include <stdbool.h>\n\n", NIL);
+	  }
 	}
       }
     }