warnings: [ /global variable/ ]
----
for (x=0; !x<2; x++) { alert(1) }
for (; !x<2; ) { alert(1) }
for (;;++x) { alert(1) }
for (;;) { alert(1) }
----
x = 0
while !x < 2
  alert 1
  x++
while !x < 2
  alert 1
loop
  alert 1
  ++x
loop
  alert 1
