extract method: allow to fold parameters if calls to fields are involved

java/java-tests/testData/refactoring/extractMethod/FoldingWithFieldInvolved.java

@@ -0,0 +1,10 @@
+class Main {
+    private String [] args;
+
+    void foo(Main m, int i) {
+        <selection>if (m.args[i] != null) {
+            System.out.println(m.args[i]);
+        }</selection>
+           
+    }
+}

java/java-tests/testData/refactoring/extractMethod/FoldingWithFieldInvolved_after.java

@@ -0,0 +1,14 @@
+class Main {
+    private String [] args;
+
+    void foo(Main m, int i) {
+        newMethod(m.args[i]);
+
+    }
+
+    private void newMethod(String arg) {
+        if (arg != null) {
+            System.out.println(arg);
+        }
+    }
+}