* lisp/progmodes/opascal.el: Tweak code to ease edebugging

* lisp/progmodes/opascal.el: Tweak code to ease edebugging

(opascal-strings): Inline in its sole use.
(opascal-save-excursion): Add Edebug spec.
(opascal-is): Remove.  Use `memq` directly instead.
(opascal--in): New pcase pattern.
(opascal-literal-end-pattern): Remove unused function.
(opascal--scan-non-whitespace-backward): New macro.
(opascal-block-start, opascal-else-start, opascal-is-use-clause-end)
(opascal-previous-indent-of, opascal-section-indent-of)
(opascal-enclosing-indent-of): Use it.
(opascal-corrected-indentation): Presume we're already at first token.
(opascal-indent-line): Use indent-line-to.
(opascal-new-comment-line): Declare obsolete.
(opascal-mode-map): Keep the default M-j binding instead.