Fixes #8585

When emmiting label of a self-recursive tail call (ie. when
performing loopification optimization) we emit the loop header
label after a stack check but before the heap check. The reason is
that tail-recursive functions use constant amount of stack space
so we don't need to repeat the check in every loop. But they can
grow the heap so heap check must be repeated in every call.
See Note [Self-recursive tail calls] and [Self-recursive loop header].