encoding.c: preserved encindex

* encoding.c (rb_enc_init): register preserved indexes.
* internal.h (ruby_preserved_encindex): move from encoding.c.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41738 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
encoding.c: validate index

* encoding.c (rb_enc_set_index, rb_enc_associate_index): validate
  argument encoding index.
* include/ruby/encoding.h (ENCODING_SET): use rb_enc_set_index()
  instead of setting inlined bits directly.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41739 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
encoding.c: use built-in encoding indexes

* encoding.c (enc_inspect, rb_locale_encindex),
  (enc_set_filesystem_encoding, rb_filesystem_encindex): use built-in
  encoding indexes directly.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41740 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
internal.h: use built-in encoding indexes

* internal.h (rb_{ascii8bit,utf8,usascii}_encindex): use built-in
  encoding indexes for optimization.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41741 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
io.c: use built-in encoding indexes

* internal.h: add UTF-{16,32}{BE,LE}.
* io.c (io_strip_bom): use built-in encoding indexes in internal.h.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41742 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
string.c: use built-in encoding indexes

* internal.h: add UTF-{16,32} dummy encodings.
* string.c (rb_str_inspect, str_scrub0): use built-in encoding indexes
  in internal.h.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41743 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
dir.c: use built-in encoding indexes

* internal.h: add UTF8-MAC.
* dir.c (rb_utf8mac_encoding): use built-in encoding indexes in
  internal.h.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41744 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
re.c: use built-in encoding indexes

* internal.h: add EUC-JP and Windows-31J.
* re.c (rb_char_to_option_kcode): use built-in encoding indexes in
  internal.h.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41745 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* doc/syntax/refinements.rdoc: add description of Module#using and
  refinement inheritance by module inclusion.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41746 b2dd03c8-39d4-4d8f-98ff-823fe69b080e