* lisp/nxml/nxml-mode.el: Treat unclosed <[[, <?, comment, and other

* lisp/nxml/nxml-mode.el: Treat unclosed <[[, <?, comment, and other
literals as extending to EOB.
(nxml-last-fontify-end): Remove unused variable.
(nxml-after-change1): Use with-silent-modifications.
(nxml-extend-after-change-region): Simplify.
(nxml-extend-after-change-region1): Remove function.
(nxml-after-change1): Don't adjust for dependent regions.
(nxml-fontify-matcher): Simplify.
* lisp/nxml/xmltok.el (xmltok-dependent-regions): Remove variable.
(xmltok-add-dependent): Remove function.
(xmltok-scan-after-lt, xmltok-scan-after-processing-instruction-open)
(xmltok-scan-after-comment-open, xmltok-scan-prolog-literal)
(xmltok-scan-prolog-after-processing-instruction-open): Treat
unclosed <[[, <?, comment, and other literals as extending to EOB.
* lisp/nxml/rng-valid.el (rng-mark-xmltok-dependent-regions)
(rng-mark-xmltok-dependent-region, rng-dependent-region-changed):
Remove functions.
(rng-do-some-validation-1): Don't mark dependent regions.
* lisp/nxml/nxml-rap.el (nxml-adjust-start-for-dependent-regions)
(nxml-mark-parse-dependent-regions, nxml-mark-parse-dependent-region)
(nxml-clear-dependent-regions): Remove functions.
(nxml-scan-after-change, nxml-scan-prolog, nxml-tokenize-forward)
(nxml-ensure-scan-up-to-date):
Don't clear&mark dependent regions.