* parse.y (rb_enc_symname_type): allow ID_ATTRSET for ID_INSTANCE,
ID_GLOBAL, ID_CLASS, ID_JUNK too. [Bug #8756]
* parse.y (rb_id_attrset): fix inconsistency with literals, allow
ID_ATTRSET and return it itself, but ID_JUNK cannot make ID_ATTRSET.
and raise a NameError instead of rb_bug() for invalid argument.
* parse.y (rb_id_attrset, intern_str): allow junk attrset ID for
Struct.
* parse.y (rb_id_attrset): check if the argument is valid type as an
attribute.
* parse.y (rb_id_attrset): allow other than ID_ATTRSET.
* parse.y (intern_str): ditto. try stem ID for ID_INSTANCE,
ID_GLOBAL, ID_CLASS, ID_JUNK too. [Bug #8756]
merge revision(s) r42479,r42490,r42509,r43083,r43084,r43085: [Backport #8756] [Backport #9248]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_0_0@44911 b2dd03c8-39d4-4d8f-98ff-823fe69b080e