Specify that StringIO#puts with nil behaves like other IO objects
Make 1.9 and 2.0 StringIO#puts print nil like other IO objects
Merge pull request #2129 from ashmoran/issue_2113_stringio_puts_nil

Fix issue 2113 StringIO puts printing nil
Update spec library/socket/socket/gethostbyname.

Add two new specs to verify that addresses in address list returned
by Socket.gethosbyname are in 'pack' format (one spec for IPv4
addresses an the other for IPv6 ones).
Update Socket.gethostbyname to respect two new specs.

Socket.gethostbyname is updated for all ruby versions.

Socket.sockaddr_in is used to transform addresses got from
Socket.getaddrinfo to packed strings. A new structure is added for IPv6
addresses so they can be transformed properly.
Fixed running Ruby finalizers at halt.
Add cleanup for unused code resource chunks

This cleans up chunks that are completely unused during GC. This makes
sure that if we have code that creates churn for code resources doens't
result in these lists growing all the time.
Fix deadlock when shutting down finalizers

There was a race here setting exit_ and waiting. We ensure we always
have the worker_lock when changing and checking exit_.
Fix race condition in setting up RString data

We only set the type in the end if everything is ready. Before we had a
race condition where type_ was already set to cRString, but the data
wasn't allocated yet. By setting up a memory barrier and setting the
type after that, we make sure all the data is initialized properly.
Fixed typo in debugger step doc.
Revert db8ab9ac. Fixes #2130.

There may be a refactoring possible here but for now it's best to
have the debugger functioning.
Removed CI tags for fixed finalizers.
Important changes missing from a1366a4.
Use interrupt_with_signal for FFI calls

This ensures that FFI calls that take longer can be interrupted when for
example an exception is raised into the thread. By changing this we make
sure a SIGVTARLM is sent in those cases so the exception can be handled
properly.

Fixes #2127
Cleanup of using stack attention

The previous change still had the stack check at the beginning of a
compiled code which caused the problems with the debugger. This change
properly removes all these checks.