Added diagnostic error when in function declaration name was omitted

compiler/testData/diagnostics/tests/recovery/namelessInJava.kt

@@ -12,6 +12,6 @@ public class Nameless {
 import p.*
 
 class K : <!INVISIBLE_MEMBER!>Nameless<!>() {
-    fun<!SYNTAX!><!> () {}
+    <!FUNCTION_DECLARATION_WITH_NO_NAME!>fun ()<!> {}
     val<!SYNTAX!><!> : Int = 1
-}
+}

compiler/testData/diagnostics/tests/recovery/namelessMembers.kt

@@ -1,7 +1,7 @@
 // !DIAGNOSTICS: -REDECLARATION
 
 class C {
-    fun<!SYNTAX!><!> () {
+    <!FUNCTION_DECLARATION_WITH_NO_NAME!>fun ()<!> {
 
     }
 

compiler/testData/diagnostics/tests/recovery/namelessToplevelDeclarations.kt

@@ -2,7 +2,7 @@
 
 package<!SYNTAX!><!>
 
-fun<!SYNTAX!><!> () {
+<!FUNCTION_DECLARATION_WITH_NO_NAME!>fun ()<!> {
 
 }