CLJS-1423: self-host: Requiring analyzer/compiler breaks unchecked Boolean

When analyzing, trap set! calls targeting
*unchecked-if* iff the value is a compile-time
boolean constant.

Otherwise, if the cljs.analyzer namespace
is required by ClojureScript code being
compiled by ClojureScript-JVM, when
the form

  (set! *unchecked-if* val)

in the :cljs conditional-compilation branch
is analyzed, it is unintentionally trapped and
the *unchecked-if* is reset to the symbol
'val (which is truthy, causing the compiler
to then emit unchecked if code).

Author: mfikes

src/main/clojure/cljs/analyzer.cljc

@@ -1589,8 +1589,9 @@
     (disallowing-recur
      (let [enve (assoc env :context :expr)
            targetexpr (cond
-                       ;; TODO: proper resolve
-                       (= target '*unchecked-if*)
+                       (and
+                         (= target '*unchecked-if*) ;; TODO: proper resolve
+                         (or (true? val) (false? val)))
                        (do
                          #?(:clj  (reset! *unchecked-if* val)
                             :cljs (set! *unchecked-if* val))