* lisp/progmodes/ruby-mode.el (ruby-beginning-of-defun)

* lisp/progmodes/ruby-mode.el (ruby-beginning-of-defun)
(ruby-end-of-defun, ruby-move-to-block): Bind `case-fold-search'
to nil.
(ruby-end-of-defun): Remove the unused arg, change the docstring
to reflect that this function is only used as the value of
`end-of-defun-function'.
(ruby-beginning-of-defun): Remove "top-level" from the docstring,
to reflect an earlier change that beginning/end-of-defun functions
jump between methods in a class definition, as well as top-level
functions.