=begin
Passing a hash without required key (:keyreq) to a method which takes keyreq: and **keyrest,
then a same hash is set to both keyreq and keyrest.
This issue was solved with changeset r39869.
Nobuhiro, thank you for reporting this issue.
Your contribution to Ruby is greatly appreciated.
May Ruby be with you.
vm_insnhelper.c: check required kwarg with resthash
vm_insnhelper.c (vm_callee_setup_keyword_arg): should check required
keyword arguments even if rest hash is defined. [ruby-core:53608]
[Bug #8139]