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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• You've added tests (if possible) to cover your change(s). Bugfix, indentation, and font-lock tests are extremely important!
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