dir.c: match plain names as-is

* dir.c (glob_pattern_type): separate names with alphabet but no
  magical from plain.
* dir.c (glob_helper): match plain names as-is to treat super-root
  same as the root.  [ruby-core:61552] [Bug #9648]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@45965 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
dir.c: reduce matching

* dir.c (glob_helper): reduce matching at non-mgaical path on
  Windows.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@45966 b2dd03c8-39d4-4d8f-98ff-823fe69b080e