[IR] Fix bug in implementation of PUSH_FRAME instruction

* Fixes a ton of rubyspec errors when AddCallProtocolInstructions
  pass is enabled. One more rubyspec failure to be investigated
  with this pass enabled before this can be considered green
  as well.
Remove all references to getMainStream[Safe].
Fix popen and process shutdown logic and update jnr-ffi.
Upate RubySpec from Rubinius repo.

RubySpec has been broken into pieces, with core, language, and
command line specs living in the Rubinius repository, and specs
for all stdlibs living in the rubysl projects.

In order to wrap up 2.1 support for JRuby 9k, we need to get the
latest specs, since there are many in our old copy that do not
pass in 2.1 or have behavioral differences.

This means that we will not have the stdlib specs available after
this commit unless we choose to stitch them back together from
rubysl projects. Given the relative coverage of rubysl specs
compared to MRI's tests for the same library, this may not be
worth the effort.
Merge branch 'master' into new_transcoder

Conflicts:
	spec/tags/ruby/core/encoding/converter/primitive_convert_tags.txt
	spec/tags/ruby/core/encoding/converter/primitive_errinfo_tags.txt