Correct generate MEPA code to references or value

This include variation of "CRVL", "CRVI" and "CREN"

Signed-off-by: Gustavo Toshi Komura <gtk10@c3sl.ufpr.br>
Update test to check modification generate MEPA code

Signed-off-by: Gustavo Toshi Komura <gtk10@c3sl.ufpr.br>
Execute make

Signed-off-by: Gustavo Toshi Komura <gtk10@c3sl.ufpr.br>