Not_a_number related bugfix (issue #622)

Signed-off-by: Adam Knapp <adam.knapp@ericsson.com>

compiler2/Value.cc

@@ -7610,6 +7610,16 @@ void Value::chk_expr_operand_execute_refd(Value *v1,
           return;
         }
         chk_expr_operandtype_int_float(tt1, the, opname, v1);
+        if (tt1 == Type::T_REAL) {
+          if (v1->get_val_Real() != v1->get_val_Real()) {
+            if (u.expr.v_optype == OPTYPE_UNARYPLUS) {
+              v1->error("`+not_a_number' is not allowed");
+            } else {
+              v1->error("`-not_a_number' is not allowed");
+            }
+            set_valuetype(V_ERROR);
+          }
+        }
         chk_expr_eval_value(v1, t_chk, refch, exp_val);
       }
       break;