add Array#flatten
Merge remote-tracking branch 'origin/master' into tim/Array#flatten
implement Thread.recursion_guard (akin to MagLev and Rubinius) and use that in Array#flatten
add Array.try_convert
this returns an int actually
Merge pull request #296 from topazproject/tim/Array#flatten

Missing Array#flatten
Avoid a copy here, use concat
this appears t obe the actually correct API
write this loop in a way that can be constant folded
Revert "this appears t obe the actually correct API"

This reverts commit f440f5f231450482333ea9a8064418f67228a470.