~/Code/rubinius ‹ruby-1.9.3›  ‹master*› $ bin/rbx compile -B -e "foo { return }"

============= :__script__ ==============
Arguments:   0 required, 0 post, 0 total
Arity:       0
Locals:      0
Stack size:  2
Lines to IP: 1: 0..9

0000:  push_self
0001:  create_block               #<Rubinius::CompiledMethod __block__ file=(snippet)>
0003:  allow_private
0004:  send_stack_with_block      :foo, 0
0007:  pop
0008:  push_true
0009:  ret
----------------------------------------

============== :__block__ ==============
Arguments:   0 required, 0 post, 0 total, (splat -2)
Arity:       -1
Locals:      0
Stack size:  2
Lines to IP: 1: 0..2

0000:  push_nil
0001:  raise_return
0002:  ret
----------------------------------------