KT-19565: J2K: Determine mutability using iterator

#KT-19565 fixed

j2k/testData/fileOrElement/mutableCollections/Iterator.kt

@@ -0,0 +1,20 @@
+import java.util.*
+
+internal class Iterator {
+
+    var mutableMap1: MutableMap<String, String> = HashMap()
+    var mutableMap2: MutableMap<String, String> = HashMap()
+
+    fun testFields() {
+        mutableMap1.values.add("")
+        mutableMap2.entries.iterator().remove()
+    }
+
+    fun testFunctionParameters(immutableCollection: Collection<String>, mutableList: MutableList<Int>) {
+        val it = immutableCollection.iterator()
+        while (it.hasNext()) {
+            it.next()
+        }
+        mutableList.listIterator().add(2)
+    }
+}