Pony seems to have a race

[kaeluka]

See this commit for a program that triggers it on my machine:

"It's a bug in pony, I only slightly modified counter.c such that
several threads send to one actor. The actor mailbox has a race that
leads to a crash. We'll need Sylvain's help to fix it without hurting
performance terribly."

Edit: more general: we need someone who knows lock free data structures to fix it without hurting performance terribly.

0c2dcf6

[TobiasWrigstad]

I am closing this for now, since the pony runtime has changed.