feat(compiler): Allow non-block bodies with loops

[alex-snezhko]

Allows for and while loops to be used without block bodies

for (let mut i = 0; i < 5; i += 1)
  print("Hello")

[spotandjake]

I think this looks great, should we add some comment formatting tests like:

for (let mut i = 0; i < 10; i += 1) /* Comment */ print("Here")