* src/syntax.c (SYNTAX_FLAGS_COMMENT_STYLEB)
(SYNTAX_FLAGS_COMMENT_STYLEC): New macros.
(SYNTAX_FLAGS_COMMENT_STYLE): Use them, add an argument.
(syntax_prefix_flag_p): New function.
(Fstring_to_syntax): Understand new "c" flag.
(Finternal_describe_syntax_value): Recognize new flag; use the
SYNTAX_FLAGS_* macros.
(scan_sexps_forward, Fparse_partial_sexp): Change representation of
comment style to accomodate the new styles.
(back_comment, forw_comment, Fforward_comment, scan_lists)
(scan_sexps_forward): Update code to obey the new comment style flag.
* src/syntax.h: Move SYNTAX_FLAGS_FOO() macros to syntax.c.
* src/casefiddle.c (casify_region): Use the new syntax_prefix_flag_p.
* lisp/progmodes/octave-mod.el (octave-mode-syntax-table): Use the new "c"
comment style.
* lisp/progmodes/scheme.el (scheme-mode-syntax-table):
* lisp/emacs-lisp/lisp-mode.el (lisp-mode-syntax-table): Remove spurious
"b" flag in "14b" syntax.
Fixes: debbugs:6834
second char of a comment-start sequence.
(scheme-sexp-comment-syntax-table): New var.
(lambda, define): Set their scheme-doc-string-elt property.
(scheme-font-lock-syntactic-face-function): Handle sexp-comments.
Use lisp-font-lock-syntactic-face-function now that it properly
handles |...| symbols.
(scheme-mode-variables): Set lisp-doc-string-elt-property,
parse-sexp-lookup-properties and font-lock-extra-managed-props.
(scheme-font-lock-syntactic-face-function): New function, to
distinguish strings from |...| symbols.
(scheme-mode-variables): Use it. Also fix up the font-lock-time
syntax-table so that #|...|# is properly highlighted.
`font-lock-defaults', also specify that "#" should
be interpreted with `word' syntax.
(scheme-font-lock-keywords-2): Also interpret "#:foo" as keyword.
(scheme-font-lock-keywords-1, scheme-font-lock-keywords-2,
scheme-font-lock-keywords): Moved here from font-lock.el.
(dsssl-mode): Move font-lock-defaults setting and running hooks.
(dsssl-imenu-generic-expression): Likewise
(scheme-mode-variables): Set imenu-syntax-alist.
(dsssl-mode): Remove `!' from font-lock-defaults. Set
imenu-syntax-alist.
