Complete new threaded Enumerator#next and remove old logic.
Split out abstract superclass for Nexters.
Fixes to prevent finalization from setting interrupt status.
Add option for lightweight enums and introduce Array#each enum.
Perf improve Enum#next by using SyncQueue instead of Exchanger.
20: Was erroneously marking kwargs as simple method if keywordrest was specified.  Basic interp kwargs done?
Try harder to shut down Nexter thread.

Don't look too close.
Make compiler hard fail for kwargs for now.
Merge pull request #715 from atambo/bignum_should_not_raise_error_when_divided_by_zero_float

Bignum#/ should not raise ZeroDivisionError if other is zero and is a Float
Merge pull request #714 from atambo/include_etc_rubyspecs

Some rubyspec additions
Merge pull request #716 from atambo/add_tags_for_failing_getsetrlimit

Add fails tags for Process.{get,set}rlimit
Merge pull request #717 from atambo/add_tag_for_failing_spawn_spec

Add fails tag to failing Kernel.spawn spec
REFACTORING: supporting flag about receiving an offset or not.
Update to invokebinder 1.2 artifact.
Remove debug flag.
IO.copy_stream should handle objects that respond to read or write. Fixes #437
Go back to known-working-but-slower Exchanger impl of #next.

The exchanger impl is still slower than the pure-Ruby +
queue impl, but it does not leak threads and appears to
reliably shut down abandoned Enumerators. We can iterate on
improving perf of this impl (and applying that knowledge to
Fiber perf) post 1.7.4.

This reverts commits d3cf2954b38110da9f8d63f46c0757ad9f451c8d
and f19a8376453656c113b9ef9adf4b365eabaf37d6.
Improved killifying of Enumerator#next thread.
Fix #497 by using nearest class's name for anon inspect prefix.
Merge pull request #722 from josedonizetti/supporting_offset

REFACTORING: supporting flag about receiving an offset or not.