CC Mode: Enhance C++ Mode raw strings to multi-line strings for any language

CC Mode: Enhance C++ Mode raw strings to multi-line strings for any language

* lisp/progmodes/cc-defs.el (cadar, caddr, cdddr): Add defsubsts for these for
when they are missing from the host Emacs.
(c-point): Add new `position' 'boll "beginning of logical line".
(c-clear-char-properties): Return the position of the lowest removed
property.

* lisp/progmodes/cc-engine.el (c-full-pp-to-literal): Fix for rare case where
LIMIT < START in parse-partial-sexp.
(c-old-beg-rs, c-old-end-rs, c-raw-string-end-delim-disrupted)
(c-raw-string-pos, c-raw-string-in-end-delim, c-depropertize-raw-string)
(c-depropertize-raw-strings-in-region, c-before-change-check-raw-strings)
(c-propertize-raw-string-id, c-propertize-raw-string-opener): Old functions
and variables removed or renamed "raw" -> "ml" and adapted.
(c-old-beg-ml, c-old-1-beg-ml, c-old-end-ml, c-beg-pos, c-end-pos)
(c-ml-string-end-delim-disrupted, c-depropertize-ml-string-delims)
(c-ml-string-delims-around-point,c-position-wrt-ml-delims)
(c-before-change-check-ml-strings, c-after-change-unmark-ml-strings)
(c-maybe-re-mark-ml-string, c-propertize-ml-string-id)
(c-propertize-ml-string-opener, c-depropertize-ml-string)
(c-depropertize-ml-strings-in-region): New functions and variables adapted and
possibly renamed from "raw" -> "ml".
(c-ml-string-make-closer-re, c-ml-string-make-opener-re)
(c-c++-make-ml-string-closer-re, c-c++-make-ml-string-opener-re)
(c-get-ml-closer, c-ml-string-opener-around-point)
(c-ml-string-opener-intersects-region, c-ml-string-opener-at-or-around-point)
(c-ml-string-back-to-neutral, c-ml-string-in-end-delim, c-neutralize-pos)
(c-neutralized-prop): New functions and variables.

* lisp/progmodes/cc-fonts.el (c-basic-matchers-before): Replace
c-font-lock-raw-strings with c-font-lock-ml-strings.
(c-font-lock-ml-strings): New function taking the place of the old
c-font-lock-ml-strings.

* lisp/progmodes/cc-langs.el (c-get-state-before-change-functions): Move
c-depropertize-CPP to the second item of the C++ entry, and replace
c-before-change-check-raw-strings by c-before-change-check-ml-strings.  Add a
new entry for Pike Mode.
(c-before-font-lock-functions): (Replace c-after-change-unmark-raw-strings by
c-after-change-unmark-ml-strings in the C++ entry, and add a new entry for
Pike Mode.
(c-ml-string-backslash-escapes, c-ml-string-non-punc-skip-chars)
(c-ml-string-opener-re, c-ml-string-max-opener-len, c-ml-string-any-closer-re)
(c-ml-string-max-closer-len, c-ml-string-max-closer-len-no-leader)
(c-ml-string-back-closer-re, c-make-ml-string-closer-re-function)
(c-make-ml-string-opener-re-function, c-ml-string-cpp-or-opener-re)
(c-cpp-or-ml-match-offset): New c-lang-defconsts and c-land-defvars.
(c-multiline-string-start-char): Remove the Pike Mode setting.

* lisp/progmodes/cc-mode.el (c-depropertize-CPP): Test for general ml strings
rather than C++ raw strings.
(c-unescaped-nls-in-string-p): Handle languages with ml strings.
(c-clear-string-fences): Fix bug with wrong parenthesisation.
(c-before-change-check-unbalanced-strings)
(c-after-change-mark-abnormal-strings, c-after-change-escape-NL-in-string):
Adapt for multi-line strings.