test: add labels and breaks count tests.

js/js.translator/testData/box/inline/multiDeclaration.kt

@@ -9,6 +9,8 @@ class A(val a: Int, val b: Int)
 inline operator fun A.component1(): Int = a
 inline operator fun A.component2(): Int = b
 
+// CHECK_BREAKS_COUNT: function=box count=0 TARGET_BACKENDS=JS_IR
+// CHECK_LABELS_COUNT: function=box name=$l$block count=0 TARGET_BACKENDS=JS_IR
 fun box(): String {
     val (a, b) = A(1, 2)
     assertEquals(1, a)