(for constant reference).

* eval.c (rb_call0): use TMP_ALLOC() instead of allocating
  a temporary array object.

* eval.c (eval): need not to protect $SAFE value.
  [ruby-core:07177]

* error.c (Init_Exception): change NameError to direct subclass of
  Exception so that default rescue do not handle it silently.

* struct.c (rb_struct_select): update RDoc description.
  [ruby-core:7254]

* numeric.c (int_upto): return an enumerator if no block is
  attached to the method.

* numeric.c (int_downto): ditto.

* numeric.c (int_dotimes): ditto.

* enum.c (enum_first): new method Enumerable#first to take first n
  element from an enumerable.

* enum.c (enum_group_by): new method Enumerable#group_by that
  groups enumerable values according to their block values.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@9880 b2dd03c8-39d4-4d8f-98ff-823fe69b080e