(f90-indent-to, f90-indent-line-no)

(f90-indent-to, f90-indent-line-no)
(f90-no-block-limit, f90-end-of-block, f90-beginning-of-block)
(f90-comment-region, f90-indent-line, f90-indent-region)
(f90-find-breakpoint, f90-block-match): Trivial simplifications.
(f90-looking-at-do, f90-looking-at-select-case)
(f90-looking-at-if-then, f90-looking-at-where-or-forall): Drop
XEmacs 19 support and simplify.
(f90-indent-new-line): No need for case-fold-search.  Simplify.
(f90-fill-region): Make marker nil when done.  Simplify.