We are going to deprecate `WITH_RUNTIME` directive. The main reason
behind this change is that `WITH_STDLIB` directive better describes
its meaning, specifically it will add kotlin stdlib to test's classpath.
Before this commit we had two statements blocks for 'for' loops:
range variable declaration + iterator variable declaration + while loop.
However, BE requires a bit different loop structure to make lowerings
properly so in this commit iterator declaration & while loop were
extracted to separate block.
Ivan Kylchik