Cases where propagation should be limited/reverted

[pfalcon]

040-bzero:

    $a6 = $a2_0;
    if (cond) {
      $a6 = $a2_0 + 0x1;
    }

Here, it would be better to have:

    $a6 = $a2_0;
    if (cond) {
      $a6 += 0x1;
    }

[pfalcon]

040-bzero:

      do {
        *(u8*)$a6 = 0x0;
        *(u8*)($a6 + 0x1) = 0x0;
        $a6 += 0x2;
      } while ($a6 != $a2_0 + $a3_0);

Condition in while. Fairly speaking, for decompilation understanding that's probably better than having a test against a variable with meaningless name. But for reusing decompiled output, constant subexpressions should be hoisted out of the loop for efficiency. (On the other hand, an optimizing compiler would do that itself.)