Implement shift operators

boot/ast.cc

@@ -1012,6 +1012,10 @@ namespace boot
                 return "or";
             case binary_operator::exclusive_disjunction:
                 return "xor";
+            case binary_operator::shift_left:
+                return "<<";
+            case binary_operator::shift_right:
+                return ">>";
         }
         __builtin_unreachable();
     };