Convert Queue and SizedQueue to rb builtin

A large part of `thread_sync.c` was migrated already, might as well
go all the way. It also allow to remove a bunch of Rdoc commands.

Author: byroot

test/ruby/test_settracefunc.rb

@@ -2226,7 +2226,7 @@ def method_for_test_thread_add_trace_func
   def test_thread_add_trace_func
     events = []
     base_line = __LINE__
-    q = Thread::Queue.new
+    q = []
     t = Thread.new{
       Thread.current.add_trace_func proc{|ev, file, line, *args|
         events << [ev, line] if file == __FILE__