proc.c: Kernel#singleton_method
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@40684 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
proc.c: Kernel#singleton_method
which returns a Method object of the singleton method.
non-singleton method causes NameError, but not aliased or zsuper
method, right now.
[ruby-core:54914] [Feature #8391]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@40684 b2dd03c8-39d4-4d8f-98ff-823fe69b080e