recursive lambda checks for functional interfaces

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

@@ -22,6 +22,6 @@ class CastInContexts {
     }
 
     {
-      int i = <error descr="Inconvertible types; cannot cast '<lambda expression>' to 'int'">(int) ()-> 1</error>;
+      int i = (int) <error descr="int is not a functional interface">()-> 1</error>;
     }
 }

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

@@ -0,0 +1,5 @@
+class Demo {
+    public static void main(String[] args) {
+        Runnable r = () -> <error descr="void is not a functional interface">() -> () -> {}</error>;
+    }
+}

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

@@ -16,7 +16,7 @@ class NoInferenceResult {
 
     void test() {
         m((String s1) ->  <error descr="Target type of a lambda conversion must be an interface">(String s2) ->  s1 + s2</error>);
-        m(<error descr="Incompatible return type <lambda expression> in lambda expression">(String s1) ->  {return (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((String s1) -> s1.length());
         m((String s1) -> s1);

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

@@ -48,7 +48,7 @@ class Test2 {
   }
 
   {
-    X<?> x = <error descr="No instance of type X<?> exists so that lambda expression can be type-checked">() -> 123</error>;
+    X<?> x = () -> 123;
     X<? extends Number> x1 = () -> 123;
     
   }