Test for IDEA-181794 Suggest completion items with type casts in stream chains

The functionality was implemented automatically after a combination of earlier commits: 9fedf66f and 80e63e2

java/java-tests/testData/codeInsight/completion/normal/StreamIncompleteDfa.java

@@ -0,0 +1,15 @@
+import java.util.List;
+import java.util.Set;
+
+class Boo {
+}
+
+class Foo extends Boo {
+    String getName() {  return "_name_"; }
+}
+
+class Test {
+    Set<String> getAllNames(List<Boo> items) {
+        return items.stream().filter(x -> x instanceof Foo).map(x -> x.getN<caret>)
+    }
+}