inference: ensure foreign variables do not participate in inference process, e.g. variables from method reference overload resolution (IDEA-154622)

java/java-tests/testSrc/com/intellij/codeInsight/daemon/lambda/NewMethodRefHighlightingTest.java

@@ -510,6 +510,10 @@ public class NewMethodRefHighlightingTest extends LightDaemonAnalyzerTestCase {
     doTest();
   }
 
+  public void testIgnoreForeignVariables() throws Exception {
+    doTest();
+  }
+
   private void doTest() {
     doTest(false);
   }