Ruby

• error.c (rb_check_trusted): new function to check an object is
  trusted.
• struct.c (rb_struct_modify), time.c (time_modify): check by the
  above function to show proper class names. [Bug #5036]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@32569 b2dd03c8-39d4-4d8f-98ff-823fe69b080e