micro-optimization chore: in for-loops change all post-{in,de}crements to pre-{in,de}crements

* reference link missing here*

This branch doesn't have anything else than changes post-increments and post-decrements to pre-increments and pre-decrements as there is a still standing optimization missing from gmqcc which does not optimize post-increments and post-decrements when they are written on lines which do not read the variable's value. They needlessly waste 1 QC instruction on it.

This can be reverted if gmqcc does get this optimization which all modern compilers have.