[ruby/rdoc] Group code object files into the same directory

(https://github.com/ruby/rdoc/pull/1114)

It's hard to distinguish code object classes by their file names alone.
And given that we have 18 such classes, it'd make the codebase a lot
easier to understand if we grouped them into a single directory.

Given that these classes are all autoloaded in `lib/rdoc.rb` instead
of required individually, this change should have minimum impact on
projects using RDoc as they generally just require `rdoc`, not individual
files. An example is Rails' `sdoc`:
https://github.com/rails/sdoc/blob/main/lib/sdoc/rdoc_monkey_patches.rb

4211292ffe

lib/rdoc/code_object/normal_class.rb

@@ -0,0 +1,92 @@
+# frozen_string_literal: true
+##
+# A normal class, neither singleton nor anonymous
+
+class RDoc::NormalClass < RDoc::ClassModule
+
+  ##
+  # The ancestors of this class including modules.  Unlike Module#ancestors,
+  # this class is not included in the result.  The result will contain both
+  # RDoc::ClassModules and Strings.
+
+  def ancestors
+    if String === superclass then
+      super << superclass
+    elsif superclass then
+      ancestors = super
+      ancestors << superclass
+      ancestors.concat superclass.ancestors
+    else
+      super
+    end
+  end
+
+  def aref_prefix # :nodoc:
+    'class'
+  end
+
+  ##
+  # The definition of this class, <tt>class MyClassName</tt>
+
+  def definition
+    "class #{full_name}"
+  end
+
+  def direct_ancestors
+    superclass ? super + [superclass] : super
+  end
+
+  def inspect # :nodoc:
+    superclass = @superclass ? " < #{@superclass}" : nil
+    "<%s:0x%x class %s%s includes: %p extends: %p attributes: %p methods: %p aliases: %p>" % [
+      self.class, object_id,
+      full_name, superclass, @includes, @extends, @attributes, @method_list, @aliases
+    ]
+  end
+
+  def to_s # :nodoc:
+    display = "#{self.class.name} #{self.full_name}"
+    if superclass
+      display += ' < ' + (superclass.is_a?(String) ? superclass : superclass.full_name)
+    end
+    display += ' -> ' + is_alias_for.to_s if is_alias_for
+    display
+  end
+
+  def pretty_print q # :nodoc:
+    superclass = @superclass ? " < #{@superclass}" : nil
+
+    q.group 2, "[class #{full_name}#{superclass}", "]" do
+      q.breakable
+      q.text "includes:"
+      q.breakable
+      q.seplist @includes do |inc| q.pp inc end
+
+      q.breakable
+      q.text "constants:"
+      q.breakable
+      q.seplist @constants do |const| q.pp const end
+
+      q.breakable
+      q.text "attributes:"
+      q.breakable
+      q.seplist @attributes do |attr| q.pp attr end
+
+      q.breakable
+      q.text "methods:"
+      q.breakable
+      q.seplist @method_list do |meth| q.pp meth end
+
+      q.breakable
+      q.text "aliases:"
+      q.breakable
+      q.seplist @aliases do |aliaz| q.pp aliaz end
+
+      q.breakable
+      q.text "comment:"
+      q.breakable
+      q.pp comment
+    end
+  end
+
+end