- if (cond) block -> if (!cond) goto end_of_block
 - local caching of current
Signed-off-by: NAlexander van Heukelum <heukelum@fastmail.fm>
Acked-by: NCyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>