KT-19565: J2K: Determine mutability using iterator

#KT-19565 fixed

j2k/testData/fileOrElement/mutableCollections/Iterator2.kt

@@ -0,0 +1,13 @@
+import java.util.ArrayList
+
+class TestMutableCollection {
+    val list: MutableList<String> = ArrayList()
+
+    fun test() {
+        val it = list.iterator()
+        while (it.hasNext()) {
+            val s = it.next()
+            if (s == "") it.remove()
+        }
+    }
+}