KT-2310: js: !! translated incorrectly (syntax ok, but logic not).

#KT-2310 Fixed

js/js.tests/test/org/jetbrains/k2js/test/semantics/MiscTest.java

@@ -148,6 +148,10 @@ public final class MiscTest extends AbstractExpressionTest {
         fooBoxTest();
     }
 
+    public void testExclExclResultIsComputedOnce() throws Exception {
+        fooBoxTest();
+    }
+
     public void testLazyPropertyGetterNotCalledOnStart() throws Exception {
         checkOutput("lazyProperty.kt", "Hello, world! Gotcha 3");
     }