JS: move expressions test to box tests

js/js.translator/testData/box/expression/misc/elvisWithThrow.kt

@@ -0,0 +1,31 @@
+package foo
+
+var i = 0
+fun bar(): Any? {
+    i++
+    return null
+}
+
+@native
+val Exception.message: String get() = noImpl
+
+fun box(): String {
+    val a: String? = null
+    try {
+        a ?: throw Exception("a")
+    }
+    catch (e: Exception) {
+        assertEquals("a", e.message)
+    }
+
+    try {
+        bar() ?: throw Exception("bar()")
+    }
+    catch (e: Exception) {
+        assertEquals("bar()", e.message)
+    }
+
+    assertEquals(1, i)
+
+    return "OK"
+}