Wrap performance warnings from the Clojure compiler

[vemv]

Create a new linter akin to :reflection and :boxed-math for the Clojure compiler's performance warnings, e.g.:

Performance warning, foo/bar.clj:58:7 - case has int tests, but tested expression is not primitive.

(there's also a less frequent warning related to recur autoboxing - make sure we wrap it too)

It should be disabled by default - generally these don't matter a lot, and sometimes they don't have a clear fix.