[#394] Declare ? character as symbol with p flag

  ? must be treated as a symbol inside symbols but as a prefix within
  conditional prefixes like #? and #?@.

Author: vspinu

CHANGELOG.md

@@ -3,8 +3,8 @@
 ## master (unreleased)
 
 ### Bugs fixed
-
-* [#394](https://github.com/clojure-emacs/clojure-mode/issues/394): `#` character now has prefix syntax class. 
+* [#394](https://github.com/clojure-emacs/clojure-mode/issues/394): `?` character is now treated as prefix when outside symbols.
+* [#394](https://github.com/clojure-emacs/clojure-mode/issues/394): `#` character now has prefix syntax class.
 * Fixed indentation of `definterface` to match that of `defprotocol`.
 * [#389](https://github.com/clojure-emacs/clojure-mode/issues/389): Fixed the indentation of `defrecord` and `deftype` multiple airity protocol forms.
 

clojure-mode.el

@@ -258,6 +258,7 @@ Out-of-the box clojure-mode understands lein, boot and gradle."
     (modify-syntax-entry ?\} "){" table)
     (modify-syntax-entry ?\[ "(]" table)
     (modify-syntax-entry ?\] ")[" table)
+    (modify-syntax-entry ?? "_ p" table) ; prefix outside of symbols
     (modify-syntax-entry ?~ "'" table)
     (modify-syntax-entry ?^ "'" table)
     (modify-syntax-entry ?@ "'" table)