Inline and fix syntax table

[yuhan0]

In Clojure single quotes ' can be part of a symbol literal anywhere except the head, this is stated explicitly in https://clojure.org/reference/reader and recently confirmed by Alex Miller on the Clojurians Slack.

Changing the syntax of ' in the syntax table affects the output of functions like (thing-at-point 'symbol) which currently does not treat quotes as part of the symbol. This in turn affects cider-symbol-at-point and dependent functions likecider-doc, which currently does not work on vars named eg. foo' or hawai'i

I also took the liberty of inlining the definition of clojure-mode's syntax table rather than inheriting and overriding bits from emacs-lisp-mode (which in turn inherits from lisp-mode), making it simpler to understand it as a whole.

Also added commas as whitespace to the syntax table, this helps with some edge cases where [:space:] is used in a font-lock regex.

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[bbatsov]

Great changes!

I also took the liberty of inlining the definition of clojure-mode's syntax table rather than inheriting and overriding bits from emacs-lisp-mode (which in turn inherits from lisp-mode), making it simpler to understand it as a whole.

I've been meaning to this for a very long time, so it's the right move. (see #270)

You'll have to look into the build failures and add some changelog entry.

[yuhan0]

Fixed the emacs-25 build failure, I didn't realise string-trim's optional argument was a new feature in 26. The emacs-master failure was there in previous PRs and seems to be some unrelated checkdoc bug.

I also just realised that this would introduce a breakage in the current cider-symbol-at-point when called on quoted symbols. I could open a PR for Cider with my changes, hopefully users who upgrade packages would do both together?

[bbatsov]

I guess they do, so this shouldn't be a big problem.

[bbatsov]

Thanks for tackling this!