Fix translation of labels with non-identifier names in JS BE

See KT-18027

js/js.translator/testData/box/labels/peculiarNames.kt

@@ -0,0 +1,18 @@
+// EXPECTED_REACHABLE_NODES: 487
+fun box(): String {
+    var log = ""
+
+    var i = 0
+    `!`@while (true) {
+        log += "i=$i;"
+        for (j in 1..3) {
+            log += "j=$j;"
+            if (i++ + j > 5) break@`!`
+            log += "!"
+        }
+    }
+
+    if (log != "i=0;j=1;!j=2;!j=3;!i=3;j=1;!j=2;") return "fail: $log"
+
+    return "OK"
+}