vm_method.c: [DOC] example of respond_to_missing?

* vm_method.c (obj_respond_to_missing): [DOC] respond_to_missing? is
  used in the example of BasicObject.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@42736 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
dir.c: reduce string object

* dir.c (dir_each): get rid of allocate new string from UTF-8 string.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@42737 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
proc.c: local variable

* proc.c (umethod_bind): extract a local variable.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@42738 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
proc.c: preserve encodings

* proc.c (mnew_from_me, rb_mod_define_method, umethod_bind),
  (method_inspect): preserve class name encodings.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@42739 b2dd03c8-39d4-4d8f-98ff-823fe69b080e