[m-rev.] for review: Add new require_tail_recursion pragma.

[Zoltan Somogyi]

On Mon,  7 Dec 2015 16:36:10 +1100, Paul Bone <paul at bone.id.au> wrote:
> For review by Zoltan

As we discussed in person, this diff should not cause any
problems for anyone, so just commit it. That way, I can
just make the changes I think are needed instead of asking you
to make them, saving steps.

Zoltan.