comparison.  [ruby-dev:24254]

* array.c (rb_ary_diff): ditto. [ruby-dev:24274]

* array.c (rb_ary_select): ditto. [ruby-dev:24278]

* array.c (rb_ary_delete): ditto. [ruby-dev:24283]

* array.c (rb_ary_rindex): ditto. [ruby-dev:24275]

* array.c (rb_ary_initialize): element size might change during
  initializing block.  [ruby-dev:24284]

* dir.c (dir_s_chdir): avoid memory leak and unnecessary chdir to
  the original directory when exception has caused in changing
  direcotry or within block.  thanks to Johan Holmberg
  <holmberg@iar.se> [ruby-core:03446]


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_8@6922 b2dd03c8-39d4-4d8f-98ff-823fe69b080e