KT-19565: J2K: Determine mutability using iterator

#KT-19565 fixed

j2k/testData/fileOrElement/mutableCollections/Iterator.java

@@ -0,0 +1,19 @@
+import java.util.*;
+
+class Iterator {
+
+    Map<String, String> mutableMap1 = new HashMap<>();
+    Map<String, String> mutableMap2 = new HashMap<>();
+
+    void testFields() {
+        mutableMap1.values().add("")
+        mutableMap2.entrySet().iterator().remove();
+    }
+
+    void testFunctionParameters(Collection<String> immutableCollection, List<Integer> mutableList) {
+        for (Iterator<String> it = immutableCollection.iterator(); it.hasNext(); ) {
+            it.next();
+        }
+        mutableList.listIterator().add(2);
+    }
+}

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)
+    }
+}

j2k/testData/fileOrElement/mutableCollections/Iterator2.java

@@ -0,0 +1,14 @@
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.List;
+
+public class TestMutableCollection {
+    public final List<String> list = new ArrayList<>();
+
+    public void test() {
+        for (Iterator<String> it = list.iterator(); it.hasNext(); ) {
+            String s = it.next();
+            if (s.equals("")) it.remove();
+        }
+    }
+}

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()
+        }
+    }
+}