* lisp/progmodes/sh-script.el (sh-here-doc-open-re): Don't rely on the

* lisp/progmodes/sh-script.el (sh-here-doc-open-re): Don't rely on the
font-lock-syntax-table remappings.
(sh-here-doc-markers, sh-here-doc-re): Remove.
(sh-font-lock-close-heredoc): Remove.
(sh-syntax-propertize-here-doc): New function.
(sh-font-lock-open-heredoc): Set the sh-here-doc-marker property
instead of the sh-here-doc-re.
(sh-font-lock-paren): Don't do anything in comments or strings.
Handle line continuations.  Accept a few more chars.
Don't rely on the font-lock-syntax-table remappings.
`esac' is not a valid pattern.
(sh-syntax-propertize-function): Handle here-docs differently, so we
don't bother syntax-propertizing the insides.

Fixes: debbugs:7947