Implement semantic of the For statement

[meevee98]

For is one of the control flow statements that consists in the repetition of a block of instruction a given number of times.

This is the syntax of the for loop in the PNP language:

para <control-variable> de <initial-value> ate <final-value> passo <increment-value> repita
    <block of instructions>
fim

Following that syntax, the for-loop iteration can start and end at any value since the values have both the same type. The step of increment can be omitted with the default value of 1.

para <control-variable> de <initial-value> ate <final-value> repita
    <block of instructions>
fim