Made foreach work with nullable iterables

tests/testData/ast/list/file/ForEach.jav

@@ -0,0 +1,14 @@
+import java.util.*;
+
+public class ForEach {
+    public void test() {
+        ArrayList<Object> xs = new ArrayList<Object>();
+        List<Object> ys = new LinkedList<Object>();
+        for (Object x : xs) {
+            ys.add(x);
+        }
+        for (Object y : ys) {
+            xs.add(y);
+        }
+    }
+}

tests/testData/ast/list/file/ForEach.kt

@@ -0,0 +1,15 @@
+import java.util.*
+public open class ForEach() {
+public open fun test() : Unit {
+var xs : ArrayList<Any?>? = ArrayList<Any?>()
+var ys : MutableList<Any?>? = LinkedList<Any?>()
+for (x : Any? in xs!!)
+{
+ys?.add(x)
+}
+for (y : Any? in ys!!)
+{
+xs?.add(y)
+}
+}
+}