fix for issue #1634 -- for passing a closure to exported Go function

[rcoreilly]

This fixes issue #1634

includes special case for defer function.

I could remove or significantly reduce the comment description, and just have that here for future reference:

// per #1634, if v is already a func, then don't re-wrap! critically, the original wrapping
// clones the frame, whereas the one here (below) does not clone the frame, so it doesn't
// generate the proper closure capture effects!
// this path is the same as genValueAsFunctionWrapper which is the path taken above if
// the value has an associated node, which happens when you do f := func() ..

[mvertes]

Thank you for fixing this bug.

Ok to me, once the linter error on test case is fixed.

[mvertes]

LGTM

[traefiker]

🚫 failed to update: update branch: PUT https://api.github.com/repos/traefik/yaegi/pulls/1646/update-branch: 403 user doesn't have permission to update head repository []

[mvertes]

@rcoreilly if it is ok for you, allowing 'edit by maintainers' on next pull requests would permit us to better automate rebase at merge (when no conflicts) and manage not up-to-date branches.

In the meantime, you have to update the branch yourself, so we can proceed.

Thanks