Ruby

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