[RFC] tt1477 branch

[Peter Lobsinger]

Hi all,

I created the tt1477 branch to try to satisfy TT #1477 - provide a way
for embedders to call into parrot with variable signatures.

It provides a callback interface (Parrot_ext_call_cb) as an
alternative to the existing varargs interface (Parrot_ext_call).

I've used  ext/Parrot-Embed to demonstrate the utility of this
interface. It now marshals between perl and parrot stacks
appropriately for a given signature, so many more signatures are
supported.

Along the way, I discovered some unrelated problems in Parrot::Embed,
so fixes for those are in there as well.

I would appreciate any input.


Peter Lobsinger