flow dead if-statement optimization

[christianparpart]

PLEASE NOTE Assuming that the expression of an if-condition is side-effect free (add this property to Flow to allow optimizations based on this)?

Given the following test handler:

handler main {
  foo;
  if (expression) { }
  else { }
  bar;
}

currently translates to:

handler main {
  foo;
  expression;
  bar;
}

but should translate to:

handler main {
  foo;
  bar;
}

the trueBlock and falseBlock get eliminated already but not the conditional expression itself.