lambda constraints: proceed with return expressions (IDEA-175426)

lambda with formal types won't lead to additional constraint after return type constraint processing, thus it need to be processed additionally

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/lambda/highlighting/NoInferenceResult.java

@@ -15,8 +15,8 @@ class NoInferenceResult {
     <T> void m1(T t) { }
 
     void test() {
-        m((String s1) ->  <error descr="Target type of a lambda conversion must be an interface">(String s2) ->  s1 + s2</error>);
-        m((String s1) ->  {return <error descr="Target type of a lambda conversion must be an interface">(String s2) ->  s1 + s2</error>;});
+        m(<error descr="Object is not a functional interface">(String s1) ->  (String s2) ->  s1 + s2</error>);
+        m(<error descr="Object is not a functional interface">(String s1) ->  {return (String s2) ->  s1 + s2;}</error>);
 
         m((String s1) -> s1.length());
         m((String s1) -> s1);

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/lambda/newLambda/LambdaWithFormalTypeParameters.java

@@ -0,0 +1,20 @@
+
+import java.io.IOException;
+import java.util.Optional;
+
+class GenericClass {
+  <E extends Throwable> void build(Test<E, Optional<Integer>> test) { }
+
+  {
+    build((IOException ex) ->  returnOptional());
+  }
+
+  private static <T> Optional<T> returnOptional() {
+    return null;
+  }
+
+  @FunctionalInterface
+  interface Test<E, T> {
+    T evaluate(E ex);
+  }
+}