Include function "procura_prox_simb"

Function "procura_prox_simb" find next symbol stack up
to another symbol.

Signed-off-by: Gustavo Toshi Komura <gtk10@c3sl.ufpr.br>
Include MEPA code to atribuition of return functions

Signed-off-by: Gustavo Toshi Komura <gtk10@c3sl.ufpr.br>
Update test to check atribuition to return functions

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

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