* object.c (rb_any_to_a): declare Object#to_a to be obsolete.
* object.c (rb_Array): do not convert nil into [] automagically.
* object.c (rb_Integer): use "to_int" instead of
"to_i". [experimental]
* object.c (nil_to_f): new method.
* object.c (rb_Integer): Symbols and nil should cause error.
* object.c (rb_Float): nil should cause error.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@2608 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
